System for amplifying nucleic acids

Abstract

The invention relates to a system for amplifying nucleic acids, in particular by means of a polymerase chain reaction, comprising a fluid receptacle (1), in particular a microtiter plate or a microchip, and a reaction mixture (2), which contains at least one nucleic acid (2.1) to be amplified, a polymerase enzyme, a buffer medium (2.2), a plurality of excitable nanoparticles (3), preferably nanostars or nanorods, and quantification means, in particular a fluorescent and / or intercalating nucleic acid dye, the reaction mixture (2) being receivable in the fluid receptacle (1). The system further comprises a reaction chamber (4), which has excitation means, the fluid receptacle (1) preferably being introducible into the reaction chamber (4) and the excitation means (5) being designed to excite the nanoparticles (3); the nanoparticles (3) are designed to generate heat in the excited state; and the reaction chamber (4) has a detection device (6), which is designed to excite the quantification means and quantitatively and / or qualitatively detect same, said excitation means being near-infrared radiation emitters (5).

Description

[0001] Description

[0002] Nucleic acid amplification system

[0003] Technical field

[0004] The invention relates to a system for the amplification of nucleic acids, in particular for carrying out polymerase chain reactions. Furthermore, the invention relates to a method for operating a system for the amplification of nucleic acids.

[0005] State of the art

[0006] Systems for nucleic acid amplification are well-established. They enable the amplification and detection of DNA via polymerase chain reactions (PCR) and quantitative PCRs, which are among the most fundamental methods in molecular biology and diagnostics. The DNA amplification process comprises a series of temperature-controlled cycles, each consisting of a step of DNA denaturation, hybridization, and elongation, all occurring at precisely controlled temperatures. Denaturation takes place at approximately 87–98°C, hybridization at approximately 50–60°C, and elongation at approximately 70–72°C.

[0007] Temperature control is achieved using various well-known systems, such as electrical heating, Peltier elements, infrared waves, and magnetic induction. However, all of these methods share the disadvantage that raising and especially lowering the temperature within a PCR cycle takes a relatively long time, meaning that even the fastest instruments can take up to a minute to complete a single cycle. Given the large number of cycles in a typical PCR run, usually 20 to 50 cycles, this can result in a significant time commitment.

[0008] Another method for temperature control in DNA amplification is the thermoplasmonic technique, in which nanoparticles are excited by electromagnetic waves. Here, the nanoparticles absorb the electromagnetic waves of a laser and generate localized heat, with the absorption efficiency significantly increased by localized surface plasmon resonance. When the laser is switched off, the generated heat dissipates rapidly into the surrounding environment, resulting in a cooling phase of just a few seconds. Typically, the DNA to be amplified is bound to the nanoparticles via a chemical preparation step, thus exposing it to the locally generated heat for short periods.The methods known from the prior art usually employ spherical and partially magnetic nanoparticles, which can be removed from the buffer medium or locally bound by applying a magnetic field and are primarily excited by waves in the visible light range. However, the necessary wavelength ranges have the disadvantage that they interfere with the detection of DNA dyes for quantifying DNA concentrations and, furthermore, lead to the bleaching of the often photosensitive dyes, thus impairing the detection results.

[0009] Disclosure of the invention

[0010] The present invention overcomes the problems of the prior art and realizes a system for the amplification of nucleic acids which achieves a particularly compact, efficient and fast solution for polymerase chain reactions.

[0011] This problem is solved by a system for the amplification of nucleic acids, in particular by polymerase chain reaction, comprising a fluid receptacle, in particular a microtiter plate or a microchip, and a reaction mixture comprising at least one nucleic acid to be amplified, a polymerase enzyme, a buffer medium, a plurality of excitable nanoparticles, preferably nanostars and / or nanorods, and quantifying agents, in particular a fluorescent and / or intercalating nucleic acid dye, wherein the reaction mixture is receptacleable in the fluid receptacle, further comprising a reaction chamber which has excitation agents, wherein the fluid receptacle is preferably introduceable into the reaction chamber and the excitation agents are configured to excite the nanoparticles, wherein the nanoparticles are configured to generate heat in the excited state, and wherein the reaction chamber has a detection device.which is designed to stimulate the means of quantification and to capture data quantitatively and / or qualitatively.

[0012] According to the invention, the excitation means are near-infrared radiation emitters.

[0013] Advantageous embodiments of the system according to the invention for the amplification of nucleic acids are the subject of the following description and description of figures, as well as the dependent claims.

[0014] The features described and claimed in the device shall also be deemed to be disclosed and claimable in the corresponding process, and vice versa. Preferably, the nanoparticles are non-spherical nanoparticles, in particular nanorods or nanostars. The non-spherical shape has the advantage that the dimensions of the nanoparticles can be selected in more than one spatial direction, in order to achieve both effective absorption of near-infrared radiation, preferably by selecting a length on the order of a wavelength of the near-infrared radiation, and a shape and, indirectly, mass for controlling the sedimentation time, particularly taking Stokes' equation into account, by selecting at least one further length.For example, the nanoparticles, as nanorods, have a length of between 500 and 1500 nm, preferably between 700 and 1200 nm, e.g., 810 nm, at least in one direction, with a diameter between 50 and 150 nm, e.g., 100 nm, preferably with a length-to-diameter aspect ratio between 7 and 10. Nanoparticles in the form of nanostars, for example, have a central diameter (i.e., without considering the spike lengths) between 100 and 250 nm, e.g., 130 nm or 200 nm, and a spike length between 50 and 100 nm, e.g., 70 nm. It can be particularly advantageous for the nanoparticles to be unbound, i.e., without the nucleic acids to be amplified being bound to them, and thus freely present in the buffer medium. The advantageous nanostar nanoparticles are, in particular, gold nanostar particles, although other precious metals are also conceivable.In this context, star-shaped nanoparticles with a spherical core and ray-like extensions are called nanostars, and rod-shaped nanoparticles are called nanorods.

[0015] The fluid intake is advantageously divided into a multitude of sample receptacles, which are also commonly referred to as "wells." The wells can be designed, in particular, as recesses on the surface of a substrate, for example, as cavities in a silicon substrate. For example, the recesses, which are preferably spaced apart from one another, for example, in a pattern, are in the form of small pots. The reaction chamber can be configured to accommodate fluid intakes, in particular wells, with varying numbers and capacities of sample receptacles, for example, by means of different inserts on or in which the fluid intake can be arranged. The nucleic acid amplification system can be operated manually and / or be integrated into an automated system, for example, a laboratory robot or a lab-on-a-chip system.The reaction chamber can therefore be, for example, a thermocycler or a microfluidic system. Furthermore, it can be advantageously provided that the reaction mixture has a total volume of less than 10 microliters, in particular less than 5 microliters, most preferably less than 2 microliters, and most preferably less than 1.5 microliters.

[0016] For example, the near-infrared radiation emitters can include lasers. In the present context, near-infrared radiation emitters are not necessarily defined as radiation sources that can emit light exclusively in the near-infrared spectrum. It is possible that the near-infrared radiation emitters are designed solely for the emission of near-infrared radiation, or that the near-infrared radiation emitters are configured to emit near-infrared radiation in addition to other spectra, with near-infrared radiation being the radiation used for the system according to the invention.

[0017] Preferably, the quantifying agent is an intercalating nucleic acid dye, for example, SYBR green. The detection device is configured to excite the quantifying agent, in particular by emitting light of a specific wavelength from a light source, and to capture and preferably evaluate the signal reflected by the quantifying agent, for example, using a camera. It can be advantageously provided that the detection device offers adjustable settings, such as different filters for fluorescence, to allow its use with various common quantifying agents.

[0018] The invention recognizes that by using the near-infrared spectrum, which denotes the non-visible region of the electromagnetic spectrum from 780 to 3000 nm, interference of the nanoparticles with commonly used DNA detection methods and dyes is avoided. Thus, DNA samples produced by the nucleic acid amplification system can be quantified without the need for the time-consuming removal of the nanoparticles from the reaction mixture or the time-consuming and costly purification of the DNA. Furthermore, the waves of the near-infrared spectrum do not bleach the quantifying agents, which makes quantitative PCR, which requires the presence of a DNA dye in the reaction mixture during the amplification process, possible with the thermoplasmonic method in the first place.The thermoplasmonic method can significantly reduce the time required for a PCR cycle, resulting in a substantial reduction in time expenditure, particularly in high-throughput applications such as diagnostics.

[0019] According to a first advantageous embodiment, the nanoparticles can be configured as nanostars and / or nanorods, wherein the length of the nanostars' radial extensions and / or the radius of their core, and / or the length of the nanorods, are configured such that a defined sedimentation time can be set. Advantageously, the nanoparticles are configured as gold nanostars. By advantageously adjusting the length of the nanoparticles, in particular the nanorods or the radial extensions and cores of the nanostars, the sedimentation time—i.e., the time until the nanoparticles mixed in the reaction mixture have settled at the bottom of the fluid reservoir—can, as mentioned above, preferably be adjusted such that more than one excitation cycle and / or PCR cycle, and more preferably all excitation cycles and / or PCR cycles, can take place before the nanoparticles have settled.This allows for the particularly advantageous provision of differently adapted nanoparticles, especially nanorods or nanostars, for various applications and / or PCR protocols.

[0020] According to a further advantageous embodiment, the nanostars can be configured with a length of radial extensions (tooth length) of 50 to 80 nm, preferably 60 to 70 nm, and / or have a central diameter of 100 to 250 nm, preferably 130 to 180 nm. These relative proportions have proven particularly advantageous, especially for achieving ideal absorption of the rays, particularly at a wavelength of 1100 nm, and a relatively short sedimentation time, while still advantageously allowing a complete PCR run before sedimentation is finished. Preferably, the nanorods have a length-to-diameter aspect ratio between 7 and 10, for example, with a length of 810 nm and a diameter of 100 nm.According to a further advantageous embodiment, the near-infrared radiation emitters can be arranged below the fluid reservoir and the detection device above the fluid reservoir, or both the near-infrared radiation emitters and the detection device can be arranged above the fluid reservoir. In this latter configuration, the near-infrared radiation emitters are advantageously arranged such that they transmit the radiation through the bottom of the fluid reservoir, thereby exciting the nanoparticles in the reaction mixture, while the detection device can excite and detect the quantifiers from the top of the fluid reservoir. This allows for simultaneous excitation of the nanoparticles and detection of the quantifiers without interference between the light emitted by the detection device and the near-infrared radiation.Alternatively, the detection device and the excitation means can both be arranged above or below the fluid intake, resulting in a more compact design of the system.

[0021] According to a further advantageous embodiment, the near-infrared radiation emitters can be configured to generate light in the wavelength range of 900 to 1400 nm, particularly preferably at least approximately 980 nm or 1200 nm. Preferably, the advantageous wavelengths of 980 nm and 1200 nm can both be encompassed in one system by different near-infrared radiation sources, which can be switched on as needed. In particular, nanoparticles designed as nanorods are used when using the wavelength of 1200 nm, and nanostars when using the wavelength of 980 nm. In an advantageous embodiment, the near-infrared radiation emitters can further comprise a polarizer.

[0022] According to a further advantageous embodiment, the fluid receptacle may comprise quartz or silicon. In particular, as described above, the fluid receptacle may comprise several recesses on a surface of a silicon substrate or a quartz substrate, wherein the recesses have, for example, a diameter between 200 and 500 micrometers (pm), for example, 350 pm, and a depth between 100 and 500 pm, for example, 200 pm, with an exemplary volume between 1 and 1000 nanoliters (nl), preferably between 1 and 500 nl, and particularly preferably between 1 and 100 nl, for example, 19.5 nl. Preferably, the silicon substrate or the quartz substrate may at least partially form the microchip. Advantageously, the fluid receptacle may consist of quartz or silicon.This offers advantages in standardizing work processes, as quartz and silicon are common materials for fluid imaging, particularly in microtiter plates or lab-on-a-chip systems. Silicon plates with nanorods and near-infrared emitters with a wavelength of 1200 nm are preferred. Quartz plates are preferably used with nanostars and near-infrared emitters with a wavelength of 980 nm. Alternative materials for fluid imaging, such as borosilicate, glass, or aluminum oxide, are also conceivable. Preferably, near-infrared emitters for which silicon or quartz is transparent are used for wells in silicon or quartz. For example, in the case of silicon, such as a silicon substrate with wells, one or more near-infrared emitters are used that emit light with a wavelength above 1180 nm, for example, at 1200 nm.This has the advantage that the contents of the wells, especially the reaction mixture, can be heated and cooled very quickly. The small size of the well volumes and the transparency of the silicon or quartz allow for rapid heating, while the transparency prevents the silicon or quartz from heating up, thus ensuring rapid cooling of the well contents. Furthermore, multiple wells offer the advantage over a single large volume that the nanoparticles can be heated more efficiently, since the wells provide more surface area per unit volume, allowing a greater proportion of the nanoparticles to be directly exposed to near-infrared radiation.

[0023] According to a further advantageous embodiment, the near-infrared radiation emitters can be formed by, preferably, a plurality of surface emitters or light-emitting diodes, which can be activated independently of one another. The embodiment with independently activatable surface emitters or light-emitting diodes is particularly preferred, offering advantages especially in lab-on-a-chip applications, such as the ability to execute different heating and / or PCR protocols for different areas or wells of the fluid receptacle. According to a further advantageous embodiment, cooling means can be included, wherein the cooling means are arranged above, and preferably on, the surface of the fluid receptacle and / or, preferably, within a flow channel, below the fluid receptacle.The cooling agent can be, for example, a cool oil film arranged on the surface of the fluid receptacle and / or a continuous flow of cool fluid, particularly water, is established in the flow channel. The cooling agent can further reduce the duration of a heating and / or PCR cycle by shortening the cooling time after excitation of the nanoparticles. In this context, the surface of the fluid receptacle, or the upper side of the fluid receptacle, refers to the side of the fluid receptacle where the openings for receiving the reaction mixture are located.

[0024] According to a further advantageous embodiment, a protective device, in particular a mirror and / or a bandpass filter, may be included, wherein the protective device is arranged between the excitation means and the detection device, particularly above the fluid intake. This advantageously reduces interference with the detection device caused by near-infrared radiation radiating beyond the fluid intake to the detection device.

[0025] The problem described above is further solved by a method for operating a system for the amplification of nucleic acids, in particular for carrying out a polymerase chain reaction, comprising the provision of a fluid receptacle, in particular a microtiter plate or a microchip, and a reaction mixture comprising at least one nucleic acid to be amplified, a polymerase enzyme, and a buffer medium, wherein the buffer medium comprises a plurality of excitable nanoparticles, preferably nanostars and / or nanorods, as well as quantifying agents, in particular fluorescent and / or intercalating nucleic acid dye, and a receptacle containing the reaction mixture in the fluid receptacle, further preferably comprising introducing the fluid receptacle into a reaction chamber containing excitation agents, and exciting the nanoparticles by the excitation agents.wherein the nanoparticles generate heat in the excited state and encompass excitation and quantitative and / or qualitative detection of the quantifying agents by a detection device associated with the reaction chamber. Alternatively, instead of introducing the fluid receptacle into the reaction chamber, the reaction chamber can, according to a particular embodiment, already contain the fluid receptacle, and the reaction mixture is introduced into the reaction chamber for absorption into the fluid receptacle.

[0026] According to the invention, the excitation means are near-infrared radiation emitters.

[0027] To avoid unnecessary repetition, reference is made to the previously described nucleic acid amplification system regarding the advantages of the method for operating a system for the amplification of nucleic acids.

[0028] The present invention will now be explained in more detail with reference to drawings that are merely schematic and exemplary embodiments of the invention.

[0029] Brief description of the drawings

[0030] Fig. 1 Schematic representation of the excitation and sedimentation of nanoparticles, as well as the detection of the quantifying agents

[0031] Fig. 2a Overview of the system for nucleic acid amplification

[0032] Fig. 2b Partial representation of the system System for nucleic acid amplification with cooling agent

[0033] Figure 1 shows a schematic fluid image 1 containing a reaction mixture 2. The reaction mixture 2 comprises a nucleic acid 2.1 to be amplified, in a buffer medium 2.2, a quantifier, and a plurality of nanoparticles 3. In the present example, the nanoparticles 3 are configured as, in particular, gold nanostars, although it is also conceivable that the nanoparticles 3 are configured as nanorods. The nanoparticles 3 and the nucleic acid 2.1 are not chemically bonded to each other; rather, the nanoparticles and / or nucleic acids are present unbound in the buffer medium 2.2. Near-infrared radiation emitters 5 are arranged below the fluid image 1, illuminating it from bottom to top with light in the wavelength range of 900 to 1400 nm, particularly preferably 980 nm or 1200 nm.The nanoparticles 3 absorb the light and are excited into a state in which they generate heat, thereby heating the reaction mixture 2, specifically to the temperatures required for the individual steps of PCR and thus nucleic acid amplification. After the near-infrared radiation emitters 5 are switched off, the nanoparticles 3 leave the excited state and no longer produce heat, causing the previously generated heat to dissipate into the surroundings and the reaction mixture 2 to cool down.

[0034] The previously described process can be repeated as often as desired until the nanoparticles 3 settle at the bottom of the fluid reservoir 1. For Nanostars, this sedimentation time can be adjusted to a desired duration by varying the lengths of the radial projections and the inner radius, as well as the ratio of the rays to the radius. It is particularly advantageous to adjust the sedimentation time so that a complete PCR, especially with approximately 40 cycles in 10 minutes, can be completed before the Nanostars have settled at the bottom of the fluid reservoir 1.In a particular embodiment, the sedimentation time is set to between 30 and 300 seconds for a PCR cycle duration of a few seconds, for example, between 1 and 5 seconds. For instance, a sedimentation time of 300 seconds is used for a cycle duration of five seconds, or a sedimentation time of between 30 and 90 seconds, preferably between 30 and 60 seconds, for example, 40 seconds for a cycle duration of one second. After the nanoparticles have sedimented, the detection device 6 detects the quantifiers in the reaction mixture, thereby measuring the concentration of the amplified nucleic acid. It is also conceivable that the concentration of the nucleic acid is measured during amplification or between amplification steps. The quantifiers are preferably intercalating DNA dyes that fluoresce when bound to nucleic acid.The detection device 6 preferably comprises a light source for exciting the quantifiers and a camera for capturing the signal of the quantifiers. Advantageously, for example, various filters may be provided which specify the captured signal or make it graphically visible.

[0035] Figure 2a shows a system for the amplification of nucleic acids with a reaction chamber 4. A fluid reservoir 1 is located in the reaction chamber 4, which has a plurality of wells containing the reaction mixture 2. The fluid reservoir 1 is preferably made of silicon or quartz. The wells are, for example, formed as cavities on the surface of a silicon or quartz substrate. For example, the wells have a diameter between 200 and 500 pm and a depth between 100 and 500 pm. The reaction mixture 2 comprises a buffer medium 2.2, for example, a commercially available PCR buffer, a nucleic acid to be amplified, quantifiers, for example, SYBR Gold or PicoGreen, and excitable nanoparticles, for example, nanostars or nanorods, particularly made of gold or other precious metals.Near-infrared radiation emitters 5 are arranged beneath the fluid reservoir 1, illuminating it from bottom to top with light in the wavelength range of 900 to 1400 nm, particularly preferably 980 nm or 1200 nm. The nanoparticles 3 absorb the light and are excited to a state in which they generate heat, thereby heating the reaction mixture 2, in particular to the temperatures required for the individual steps of carrying out PCR and thus amplification of the nucleic acid. After the near-infrared radiation emitters 5 are switched off, the nanoparticles 3 leave the excited state and no longer produce heat, causing the previously produced heat to dissipate into the surroundings and the reaction mixture 2 to cool down.

[0036] The reaction chamber 4 further comprises a detection device 6, which detects the quantifiers in the reaction mixture 2, thereby measuring the concentration of the amplified nucleic acid. The detection device 6 preferably comprises a light source for exciting the quantifiers and a camera for capturing the signal of the quantifiers. Advantageously, various filters can be provided, for example, to specify the captured signal. A protective device 9, for example a mirror or bandpass filter, is arranged between the near-infrared radiation emitters 5 and the detection device 6. This device prevents the residual radiation from the near-infrared radiation emitters from reaching the detection device 6 and causing interference. Advantageously, the protective device 9 reflects the residual radiation, in particular back onto the reaction mixture 2.

[0037] Figure 2b shows only a partial embodiment of the previously described system for the amplification of nucleic acids, including cooling agents. Here, the near-infrared radiation emitters 5 are arranged below the fluid receptacle 1, although it is equally conceivable that the near-infrared radiation emitters 5 are arranged above the fluid receptacle 1. The reaction mixture 2 comprises a buffer medium 2.2, for example, a commercially available PCR buffer, a nucleic acid to be amplified, quantifiers, for example, SYBR Green, and excitable nanoparticles 3, preferably nanostars or nanorods, particularly made of gold or other precious metals. Cooling agents 7, for example, a cool oil film, are arranged on the surface of the fluid receptacle 1, particularly sealing the wells.A flow channel 8 is formed below the fluid intake 1 or in the lower area of ​​the fluid intake 1 itself, which guides cooling medium 7, for example water, preferably as a flow system.

Claims

Claims 1. System for the amplification of nucleic acids, in particular by polymerase chain reaction, comprising a fluid reservoir (1), in particular a microtiter plate or a microchip, and a reaction mixture (2) which contains at least one nucleic acid to be amplified (2.1), a polymerase enzyme, a buffer medium (2.2), comprising a plurality of excitable nanoparticles (3), preferably nanostars or nanorods, and quantifying agents, in particular fluorescent and / or intercalating nucleic acid dyes, and wherein the reaction mixture (2) is receptible in the fluid receptacle (1), further comprising a reaction chamber (4) which has excitation agents, wherein the fluid receptacle (1) is preferably receptible in the reaction chamber (4) and the excitation agents (5) are configured to excite the nanoparticles (3), wherein the nanoparticles (3) are configured to generate heat in the excited state, and wherein the reaction chamber (4) has a detection device (6) which is configured to excite the quantifying agents and to detect them quantitatively and / or qualitatively, characterized in that the excitation agents are near-infrared radiation emitters (5).

2. System for the amplification of nucleic acids according to claim 1, characterized in that the nanoparticles (3) are designed as nanostars and / or nanorods, wherein the nanostars are designed in the length of their radial extensions and / or the radius of their core, and the nanorods are designed in their length such that a defined sedimentation time and / or excitation wavelength can be set.

3. System for the amplification of nucleic acids according to claim 2, characterized in that, that the nanostars are formed with a length of the radial extensions of 50 to 80 nm, preferably 60 to 70 nm, and / or have a central diameter of 100 to 250 nm, preferably 130 to 180 nm, and / or that the nanorods have an aspect ratio length to diameter between 7 and 10, for example at a length of 810 nm and a diameter of 100 nm.

4. System for the amplification of nucleic acids according to one of claims 1 to 3, characterized in that the near-infrared radiation emitters (5) are arranged below the fluid intake (1) and the detection device (6) is arranged above the fluid intake (1) or that the near-infrared radiation emitters (5) and the detection device (6) are arranged above the fluid intake (1).

5. System for the amplification of nucleic acids according to one of claims 1 to 4, characterized in that the near-infrared radiation emitters (5) generate light in the wavelength range of 900 to 1400 nm, particularly preferably at least approximately 980 nm or 100 nm.

6. System for the amplification of nucleic acids according to one of claims 1 to 5, characterized in that the fluid intake (1) comprises quartz and / or silicon.

7. System for the amplification of nucleic acids according to one of claims 1 to 6, characterized in that the near-infrared radiation emitters (5) are formed by, preferably a plurality of, in particular independently activatable, surface emitters or light-emitting diodes.

8. System for the amplification of nucleic acids according to any one of claims 1 to 7, characterized by, Cooling means (7), wherein the cooling means (7) are arranged above, in particular on the surface, of the fluid intake (1) and / or, preferably in a flow channel (8), below the fluid intake (1).

9. System for the amplification of nucleic acids according to one of claims 1 to 8, characterized by a protective device (9), in particular a mirror and / or a bandpass filter, wherein the protective device (9) is arranged between the near-infrared radiation emitters (5) and the detection device (6), in particular above the fluid intake (1).

10. Method for operating a system for the amplification of nucleic acids, preferably according to claims 1 to 9, in particular for carrying out a polymerase chain reaction, comprising the provision of a fluid receptacle (1), in particular a microtiter plate or a microchip, and a reaction mixture (2) which contains at least one nucleic acid to be amplified (2.1), a polymerase enzyme, a buffer medium (2.2), comprising a plurality of excitable nanoparticles (3), preferably nanostars or nanorods, and quantifying agents, in particular fluorescent and / or intercalating nucleic acid dyes, and a receiving of the reaction mixture (2) in the fluid receiving (1), further preferably comprising introducing the fluid receiving (1) into a reaction chamber (4) which has excitation agents, and excitation of the nanoparticles (3) by the excitation agents, wherein the nanoparticles (3) generate heat in the excited state, and comprising excitation and quantitative and / or qualitative detection of the quantifying agents by a detection device (6) associated with the reaction chamber (4), characterized in that the excitation agents are near-infrared radiation emitters (5).

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