73results about How to "Inexpensive requirements apply" patented technology

The invention provides an aptamer electrode for detecting terramycin. The electrode is characterized in that a glassy carbon electrode is sequentially modified with a graphene-gold nanometer compound and a BSA-OTC compound from bottom to top. A signal layer is methylene blue modified aptamer having a G tetrad structure and folded under an RCA chain amplification reaction, and the content of a target product is reflected through the amount of methylene blue. The invention also provides a manufacturing method of the aptamer electrode. The aptamer electrode has the advantages of simple manufacturing method, stable performances, and good repeatability, and is suitable for terramycin detection in the medicine safety and the industrialized practical application of biosensors.

The invention discloses an electrochemical sensor for detecting isocarbophos and acetamiprid at same time and a method system of the electrochemical sensor; the electrochemical sensor comprises an electrode, a beacon probe layer, a 6-mercaptohexan-1-ol (MCH) closure layer, and a homogenous reaction product layer sequentially from inside to outside; the beacon probe layer is modified with methylene blue and ferrocene having electrochemical signals not mutually affected; a preparation method comprises: polishing the electrode, treating with H2SO4 and H2O2, and modifying the surface of the electrode with a beacon probe. The electrochemical sensor according to the invention is simple to prepare and has good performance stability, the electrode is highly repeatable, and the electrochemical sensor is applicable to the detection of isocarbophos and acetamiprid in terms of food safety and the actual application of biosensor industrialization; the electrochemical sensor can provide quick online detection for isocarbophos and acetamiprid in food, and isocarbophos and acetamiprid detection limits are 0.12 ppb and 0.37 ppb respectively.

The invention provides a biosensor for detecting 8-hydroxylaguanine DNA glycosidase activity. The biosensor comprises an exonuclease III, hairpin probes and gold nanoparticles modified by DNA on the surfaces. Through surface-enhanced Raman detection, the 8-hydroxylaguanine DNA glycosidase activity is detected. The biosensor has mild reaction conditions and a fast reaction rate. A detection methodusing the biosensor is easy to operate, has a short detection period and high detection sensitivity. The main processes based on the detection principle are carried out in a homogeneous phase so thatthe reaction speed is increased and the complexity of operation is reduced. The biosensor realizes fast, simple and sensitive detection of a target. The biosensor realizes a low preparation cost.

The invention relates to the technical field of a biosensor, and particularly relates to a fluorescence biosensor for detecting UDG (Uracil-DNA Glycosylase) on the basis of a polymerase-assisted feedback rolling circle amplification and endonuclease amplification fluorescence method. The invention aims to solve problems of both low specificity and low sensitivity of a method for detecting UDG in the prior art. The biosensor for detecting the UDG on the basis of a feedback rolling circle amplification technology achieves a rolling circle amplification effect on matching of phi29 polymerase andendonuclease IV, implements fluorescence resonance energy transfer of a fluorophore and a Quenching group and performs a homogeneous reaction on mixed liquid. A preparation method comprises: constructing a circular template and a composite probe; feeding back a rolling circle amplification signal and carrying out fluorescence detection. Specific hydrolysis of the UDG on a basic group U is utilized, and by utilizing such specific reaction, the UDG can be accurately measured and meanwhile, interference can also be avoided; by utilizing endonuclease IV circle amplification, a signal amplificationeffect is achieved.

The invention provides a biosensor for detecting streptomycin based on an aptamer. The biosensor comprises a gold electrode, wherein an MB capture probe layer, HAP and an ssDNA layer are sequentially modified on the gold electrode. The invention also provides a preparation method of the biosensor. Based on specific recognition of the aptamer and the target, the sensor has the advantages of high detection speed, low detection limit, high specificity and the like, the defects of the conventional streptomycin detection method can be overcome, and rapid and accurate quantitative determination is realized.

The invention relates to an aptamer based salmonella typhimurium detection biosensor and a preparation method thereof. Signal amplification is realized by continuous generation and cyclic utilization of Primer, and consequently high-sensitivity detection of salmonella typhimurium is realized, and lower detection limit can be acquired. The aptamer based salmonella typhimurium detection biosensor is high in specificity and sensitivity, low in cost and quick in detection. By the detection method, a salmonella typhimurium detection limit is 5-15cfu/mL, and a detection range is 1*10-1*107cfu/mL.

The invention discloses a biosensor for detecting escherichia coli. The biosensor orderly comprises a gold electrode, a glutaraldehyde-escherichia coli antibody layer, a bovine serum albumin sealing layer, an escherichia coli layer and a RCA product layer from inside to outside. The invention discloses a preparation method of the biosensor. The biosensor has stable electrode performances, good repeatability and a detection limit of 1.6*10cfu mL(-1).

The invention relates to the technical field of biosensors, and particularly relates to a fluorescent biosensor for detecting ochratoxin A based on a rolling ring amplification mediated catalytic hairpin self-assembly and incision enzyme feedback amplification method. According to the fluorescent biosensor, as for a detection mode, a fluorescence method is adopted for detection, and a luminoscopeis utilized; before detection, a padlock probe and a connecting probe form an annular template probe; then a target object is added to a homogeneous solution of a complex probe I, a complex probe II,HP 2 and HP 3, incubating is carried out for 120 minutes at 37 DEG C, and the target object and an aptamer sequence are bound; the multiple feedback amplification process is completed under the actionof a phi29 DNA polymerase and an endonuclease IV, so that signal amplification is realized; and then, the luminoscope is used for setting the excitation wavelength to be 399 nm, the fluorescence intensity at 610 nm is detected, and the detection range is 560-640 nm. Meanwhile, the invention further provides a preparation method for the biosensor. The preparation method has the advantages of beingmild in reaction condition and easy to operate.

The invention relates to the technical field of the biosensor, and especially relates to a biosensor for detecting ATP by bringing Apt-1 and Apt-2 closer by ATP and using branch HCR amplification signal. A CP-SH layer, an AP layer, a HP1-HP2-HP3-HP4 layer and a [Ru(NH3)6]3+ layer are orderly modified on an electrode; the preparation method comprises the following steps: pre-treating the electrode,modifying the CP-SH layer to an electrode surface; modifying the AP layer to the electrode surface, and modifying the HP1-HP2-HP3-HP4 layer to the electrode surface, and modifying the[Ru(NH3)6]3+ layer to the electrode surface. The high specificity detection of the target object ATP is realized by utilizing the specificity identification of the aptamer; by utilizing the effect of bring two aptamers closer by the ATP, the cyclic utilization of the target object is realized, and the effect of the first-step signal amplification is achieved. And a signal continuous enhancement effect is realizedby utilizing branch HCR.

The invention relates to the technical field of biosensors and in particular relates to a colorimetric biosensor for detecting mercury ions and a preparation method thereof. The colorimetric biosensor is prepared from the preparation method comprising the following steps: synthesizing gold nanoparticles; modifying Probe4 on surfaces of the gold nanoparticles; mixing a marked nano gold solution and a homogeneous reaction solution. According to the colorimetric biosensor provided by the invention, high-specificity detection on the target object mercury ions is realized by utilizing specific recognition of an aptamer and a T-Hg<2+>-T composite structure; strand displacement is utilized and circulating utilization of Probe2 and Probe3 is realized and the effect of amplifying a signal is realized. The problems of a method for detecting the mercury ions at the prior art that the specificity and sensitivity are relatively low and the cost is high are solved.

The invention provides a nonenzymatic biosensor for detecting activity of uracil-DNA glycosylase. The nonenzymatic biosensor comprises a UDG template strand 1, a silver nanocluster DNA template strand2, and a DNA strand 3 rich in cytosine. A fluorescence method is used for detecting the activity of the uracil-DNA glycosylase, the stimulation wave lenagth of fluoroscopic examination is 570nm, thelength of transmitted waves is 630nm, and the detection wave band is 590-720nm. The biosensor provided by the invention is good in specificity, high in sensitivity, mild in reaction condition and highin reaction speed. Because the reaction process is free from addition of external enzymes, and through silver nanocluster fluoroscopic examination, the biosensor is simple to operate, low in reactionrequirements, short in detection cycle, stable in properties, and good in repeatability, and is suitable for detection of UDG in the field of medical health.

The invention relates to the technical field of biosensors, in particular to a biosensor for detecting miRNA through S specifically recognized by miRNA, conformation change of the S and rolling ring isothermal cycle amplification, and aims to solve the problems of low specificity and sensitivity and high cost of a method for detecting the miRNA in the prior art. According to the biosensor for detecting the miRNA, an electrode is sequentially modified with an S1 layer and an RCA product layer. The preparation method comprises the following steps: pretreating the electrode; modifying the S1 layer on the surface of the electrode; and modifying the RCA product layer on the surface of the electrode. The high-specificity detection on a target object is realized by utilizing the specific recognition of the miRNA; and three-step amplification of a target object signal is realized by using a DNAzyme and rolling ring isothermal amplification technology.

The invention relates to the electrochemical sensor technology field and especially relates to an electrochemical sensor for detecting a lead ion. A CP2 layer, a HP1-HP2-HP3-CP1-AuNP layer, and a [Ru(NH3)6]<3+> layer are sequentially modified on an electrode. The manufacturing method comprises the following steps of preprocessing the electrode; modifying the CP2 layer to an electrode surface; modifying the HP1-HP2-HP3-CP1-AuNP layer to the electrode surface; and modifying the [Ru(NH3)6]<3+> layer to the electrode surface. The specific identification of a DNA enzyme is used to realize the highspecificity detection of target object lead ions. The cutting effect of the DNA enzyme of lead ion specific identification and a CHA reaction are used to realize the increase of a signal through two-step cycle and one-step amplification modes so as to realize the high-sensitivity detection of lead ions and obtain a lower detection limit. Through the connection performance of nanogold, an effect that the signal is continuously enhanced is achieved.

The invention relates to the technical field of biosensors, in particular to an electrochemical biosensor for detecting Salmonella typhimurium and provides a preparation method of the electrochemical biosensor. The electrochemical biosensor is prepared by modifying an electrode with a HAP2 layer, and homogeneously reacting a mixed liquid. An aptamer of Salmonella typhimurium is used as a recognizing matter to highly specifically detect Salmonella typhimurium in a target by making use of specific recognizing property of the aptamer; the target is recycled through the use of nucleic instrumental enzymes, and signal amplification is achieved.

The invention relates to the technical field of biosensors, and in particular to an arched probe specifically recognized by ochratoxin A (OTA) and a biosensor for detecting OTA by catalytic hairpin assembly (CHA) and chain displacement isothermal cyclic amplification, and aims to solve the problems of low specificity and sensitivity and high cost of a method for detecting OTA in the prior art. According to the biosensor for detecting OTA, an electrode is sequentially modified with an ST-BK-S1 layer, an aptamer-T-HP1-HP2-HP3-F layer and a heme layer. A preparation method comprises the followingsteps: pretreating the electrode; modifying the surface of the electrode with the ST-BK-S1 layer; modifying the surface of the electrode with the aptamer-T-HP1-HP2-HP3-F layer; and modifying the surface of the electrode with the heme layer. High specificity detection of the target OTA is realized by utilizing specificity recognition of the OTA, and two-step amplification of the target signal is realized by utilizing a CHA reaction and the chain displacement isothermal amplification technology.

The invention relates to the technical field of biosensors, and in particular to a biosensor based on a nanogold DNA molecular machine and surface enhanced Raman scattering, in order to solve the problems of relatively low method specificity and sensitivity and high cost in the method for detecting UDG activity in the prior art. A biosensor based on surface enhanced Raman scattering of a DNA molecular machine for detecting UDG activity combines the nanogold molecular machine with the surface enhanced Raman scattering to obtain homogeneous reaction mixed liquor. The preparation method comprisesthe following steps: synthesizing gold nanoparticles; modifying Hairpin Probe,Track DNA and Raman dye onto the surfaces of the gold nanoparticles; and mixing a labeled gold nano solution with a homogeneous reaction solution. The opening of the DNA molecular machine is realized by the specific cutting of incision enzyme IV, and high-sensitivity detection is realized by the surface enhanced Raman scattering; the circulation of the DNA molecular machine is achieved by using excision enzyme III, and a signal amplification role is achieved.

The invention relates to the technical field of a biosensor, in particular to detection of uracil-DNA glycosylase based on a chemiluminescence technique for driving a strand displacement reaction based on a tee structure and driving spherical nucleases based on a DNA walker technique. In order to solve the problems of being complex to operate and low in sensitivity for a method for detecting uracil-DNA glycosylase in the prior art, the invention provides a biosensor based on two nanometer technologies of the tee structure and DNA walker, and spherical nucleases are used for catalyzing luminalto be subjected to a chemiluminescence reaction for detection. The preparation method comprises the steps of preparing nano-Au, preparing spherical nucleic acid, and forming spherical nucleases in homogeneous phase for catalyzing the chemiluminescence reaction of the luminal. The uracil-DNA glycosylase is used for performing specific recognition and excision on U alkali, so as to realize target specificity detection. Besides, the DNA walker nanometer technology is used for realizing quick and high-sensitivity detection on targets.

The invention provides an electrochemical sensor for detecting mercury ions based on aptamer conformation change. The electrochemical sensor comprises an electrode, wherein the electrode is successively modified with an HAP layer and a Helper layer; the invention also provides a biological preparation method based on specific identification of the aptamer. When the electrochemical sensor provided by the invention is applied to detection, the electrochemical sensor has the characteristics of high specificity, high sensitivity, low cost and rapid detection speed.

The invention relates to the technical field of biosensors, and especially relates to a renewable electrochemical sensor for detecting trace kanamycin, and a preparation method and an application thereof. The invention aims to solve the problems of low specificity and sensitivity and high cost of the Kana detection method in the prior art. The renewable electrochemical sensor for detecting trace kanamycin is characterized in that an electrode is sequentially modified with an H3 layer, a magnetic bead-CP/H1/H2 layer and an FP layer. The preparation method comprises the following steps: pretreating the electrode; modifying the surface of the electrode with the H3 layer; extracting Kana in a water sample by using magnetic beads, and modifying the surface of the electrode with the magnetic bead-CP/H1/H2 layer; and modifying the surface of the electrode with the FP layer. The specific recognition of an aptamer by Kana is utilized; by utilizing the magnetic beads, the extraction of trace Kana is realized; an Nb.BbvCI enzyme is utilized to realize the effect of signal amplification; and the electrode regeneration process is realized by using FP.