150 results about "Dual response" patented technology

The invention relates to a one-dimensional organic semiconductor nanowire with fluorescence and photoconduction dual response for organic amine gas and a preparation method and application of the nanowire. The preparation method comprises the following steps of synthesizing a 3,4,9,10-perylenetetracarboxylic acid anhydride containing amphipathic perylene bisimide derivative to be used as a structure unit; preparing a plurality of 3,4,9,10-perylenetetracarboxylic acid anhydride containing amphipathic perylene bisimide derivatives through a mixed solution of a good solvent and a poor solvent; and carrying out self assembling under the interaction of pi-pi of 3,4,9,10-perylenetetracarboxylic acid anhydride to obtain the one-dimensional organic semiconductor nanowire. When a reticular structural porous membrane formed by knitting the one-dimensional organic semiconductor nanowire is in contact with organic amine steam, the fluorescence is quenched; when the reticular structural porous membrane is in contact with organic fatty amine steam, the photoconduction is enhanced; when the reticular structural porous membrane is in contact with organic aromatic amine steam, the photoconduction is reduced; according to the fluorescence and photoconduction response result, the reticular structural porous membrane formed by knitting the one-dimensional organic semiconductor nanowire can selectively distinguish organic fatty amine and organic aromatic amine.

The invention discloses a preparation method of electrical stimulation-near infrared dual response high strength hydrogel. The preparation method comprises the following steps: with taking a thermosensitive polymer monomer as a main raw material, adding a natural polymer to prepare thermosensitive deformable hydrogel with a semi-interpenetrating network structure; and then sequentially adsorbing an oxidizing agent and a pyrrole monomer by utilizing the swelling effect of the hydrogel so that the pyrrole monomer sufficiently permeates into a hydrogel network and is oxidized into polypyrrole by the oxidizing agent. Due to the introduction of polypyrrole, the prepared hydrogel has conductivity and near-infrared responsibility. When the hydrogel is in an energized state or is irradiated by near infrared light, temperature of the hydrogel rises, and the thermosensitive polymer network in the hydrogel structure contracts, so that volume and shape change, and light-electricity dual stimulation response is realized; meanwhile, stimulation response behaviour of the hydrogel has good sensitivity. The prepared hydrogel also has good mechanical properties and biocompatibility and can be applied to multiple fields of drug controlled release systems, memory element switches and the like.

The invention discloses biodegradable temperature/pH dual response hydrogel and a preparation method thereof. The method comprises the following steps that: a temperature response polyphosphate ester macromonomer is taken as a crosslinking agent, and reacts with a pH sensitive monomer for radical polymerization for 12 to 24 hours at a temperature of between 30 and 50 DEG C, and then the hydrogel is prepared. The hydrogel provided by the invention utilizes temperature sensitive polyphosphate ester to replace the prior temperature sensitive acrylamide polymer, and overcomes the defect that the prior temperature sensitive hydrogel is mostly formed by polymers with poor degradability. The hydrogel provided by the invention has superior water absorption, permeability, biocompatibility, degradability and temperature/pH sensitivity, is a novel artificially synthesized macromolecular hydrogel material, and is widely used in biomedicine and other prospects, for example, the hydrogel can be taken as a biomedical material such as a medicine slow release carrier or a tissue engineering cell culture support and so on.

The invention relates to a preparation method of meso-porous silicon nanoparticle with reducing/enzyme dual response and targeting property. The preparation method of the meso-porous silicon nanoparticle with the reducing/enzyme dual response and targeting property comprises the following steps: synthesizing a meso-porous silicon nanoparticle; modifying a disulfide bond on the surface of the meso-porous silicon nanoparticle by adopting a chemical method, and grafting the disulfide bond with hyaluronic acid as a targeting molecule; by taking carboxyl on the targeting molecule as a reaction site, modifying polyethylene glycol to the surface of the compound nanoparticle, thus improving biocompatibity of the nanoparticle, and connecting the hyaluronic acid molecule with the targeting effect to the surface of the nano particle, thus obtaining the meso-porous silicon nanoparticle diagnosis agent with medicinal response releasing and imaging functions. The prepared particle has good dispersity, is uniform in particle size and is easy to prepare, the prepared multifunctional diagnosis agent has good biocompatibility, medicine can be released in a tumour part in a responding manner, and diagnosis integration of the tumour can be realized.

The invention discloses a photomagnetic dual-response Pickering emulsion coalescence reaction system and its application. Firstly, Fe3O4 nano-particles are prepared by a hydrolysis process; secondly, the Fe3O4 nano-particles are used as crystal nucleus to prepare Fe3O4/TiO2 composite nano-particles by a butyl titanate hydrolysis process; thirdly, surface hydrophobic chemical modification is carried out on the Fe3O4/TiO2 composite nano-particles by the use of alkylsilane; and finally, emulsification is carried out to obtain the photomagnetic dual-response Pickering emulsion coalescence reaction system. The above method is simple and has strong operationality. Directional migration of the emulsion and recovery of the nano-particles can be realized through magnetic response (magnetism method). By photoresponse (UV irradiation), the nano-particles adsorbed on the surface of the emulsion are changed from the non-active property to the active property, thus leading to coalescence between adjacent emulsions. By simple non-intrusive methods such as the magnetism method and UV irradiation, etc., the emulsion coalescence reaction system undergoes a chemical reaction at fixed point (reaction site) and at a fixed time (response time). The photomagnetic dual-response Pickering emulsion coalescence reaction system has a good application prospect in the industry field.

The invention discloses a preparing method and application of a dual-response sandwich-type immunosensor based on TiO2mesomorphic nanomerter material. The invention is characterized in that a novel dual-response sandwich-type immunosensor is prepared by combining electrochemistry and an electrochemical luminance method on the basis of two kinds of TiO2 mesomorphic nanomerter materials, and the dual-response sandwich-type immunosensor is applicable to detection of interleukin-6. Anatase type TiO2 mesocages materials and ionic liquid are used for fixing Ru(bpy)<3>2+ and an IL-6 antibody respectively, and the Ru(bpy)<3>2+ and the IL-6 antibody are used as a signal probe and a molecular recognition probe; octahedron anatase type TiO2 mesocages materials are used for fixing IL-6 second antibody and acid phosphatase which are marked by horse radish peroxidase, and the IL-6 second antibody and acid phosphatase are subjected to a typical sandwich-type immunoreaction to conduct self-assembly on surface of the electrode to prepare the IL-6 sandwich-type immunosensor. The prepared sandwich-type immunosensor can produce electrochemistry signals and electrochemical luminance signals, wherein signal values and IL-6 concentration present linear states within a range of 10<-6>-90 pg/ml and a range of 10<-8>-90 pg/ml respectively.

The invention discloses an acid-base dual-response hollow mesoporous silica composite nano container. The nano container comprises a hollow mesoporous silica sphere core, a corrosion inhibitor and a ZIF-8 nano valve, the corrosion inhibitor is loaded in the hollow mesoporous silica sphere core, and the ZIF-8 nanometer valve coats the outer surface of the hollow mesoporous silicon dioxide sphere core. The invention also discloses self-repairing anticorrosive paint and a preparation method thereof, the hollow mesoporous silica nano-container has acid-base dual response-release functions, the compatibility and dispersibility of the nano container in a coating can be effectively improved, and the performance of the coating is prevented from being damaged by agglomeration of the nano container.

The invention provides a pH and Redox dual-response amphiphilic block copolymer as well as a preparation method and application thereof. The molecular formula of the copolymer provided by the invention is MPEG-Linker-PAE-ss-PLGA and the copolymer has a structure as shown in the formula I and can be prepared through the following steps of performing reaction to modify macromonomer methoxypolyethylene glycols (MPEG), thereby obtaining hydrophilic macromonomer (MPEG-Linker) with pH responsiveness; performing reaction to modify macromonomer polylactic acid-poly lactic-co-glycolic acid (PLGA) by use of disulfide bonds, thereby obtaining a hydrophobic macromonomer (PLGA-Cys) with Redox responsiveness; and performing michael addition reaction through a one-step method so as to obtain the copolymer. The copolymer provided by the invention can be used in systems for loading water-insoluble drug micelle, is capable of controlling slow release of loaded drugs in normal tissues, is low in release amount accumulated for a long time, and can be enriched and rapidly released in focus tissues, thereby improving the bioavailability and treatment effect of the medicaments.

The invention relates to a preparation method for a high-strength dual-network hydrogel capable of rapidly responding to both a pH value and temperature. The preparation method comprises the following steps: (1) dissolving temperature-sensitive monomer, pH-sensitive monomer and inorganic cross-linking agent modified nanometer clay in water together, placing the obtained solution in a container, carrying out stirring in an ice bath with a temperature of 0 DEG for 60 min under the protection of nitrogen until the solution is uniform and transparent, then adding an aqueous solution of a silica network precursor and continuing stirring for 30 min until the obtained mixture is uniform and transparent; (2) adding an aqueous solution of a redox initiator and a catalyst, carrying out uniform mixing under stirring, introducing nitrogen for 5 min and pouring the obtained mixture in a die with a certain shape; (3) subjecting the die to a reaction at 20 DEG C for 30 min and then to a reaction at -28 DEG C for 24 h; and (4) taking the product out and carrying out repeated water changing and soaking so as to obtain the finished hydrogel. The hydrogel prepared in the invention has obvious dual response to temperature and the pH value, excellence strength and an ultra-fast response rate; moreover, raw materials used in the invention are cheap; the preparation method is simple; and the hydrogel is expected to be used in fields like drug sustained release and dye absorption.

An array of pressure sensors and motions sensors is contained in a layered material system that includes an acoustically compliant layer and an acoustically transparent layer. The compliant layer (which vibrates in accordance with acoustical influence thereupon) is the foundation for both sensor types and is the vibratory medium for motion sensing. The transparent layer is the matrix for both sensor types and is the window permitting sound waves to reach the pressure sensors (which sense pressure of the sound waves) and the compliant layer (the vibration of which is sensed by the motion sensors). The compliant layer's exposed surface can be attached to a structure's exterior for passive sonar detection purposes. Since the pressure sensors are effective primarily for low frequency sound waves, and the motion sensors are effective primarily for high frequency sound waves, the invention is aggregately effective for a broad band spanning low and high frequencies.

The invention relates to a preparing method of carboxymethyl chitosan/graphene oxide/poly(N-isopropylacrylamide) nanocomposite hydrogel. In preparation, the method includes the steps of conducting even mixing to obtain carboxymethyl chitosan/graphene oxide/ N-isopropylacrylamide dispersion liquid containing photoinitiator, adding an activating agent to obtain a mixed solution, making the mixed solution react under the room temperature and nitrogen protection conditions to obtain carboxymethyl chitosan/graphene oxide crosslinked and cured hydrogel, and finally conducting ultraviolet irradiationto obtain the carboxymethyl chitosan/graphene oxide/poly(N-isopropylacrylamide) nanocomposite hydrogel. The finally prepared nanocomposite hydrogel has the pH/temperature dual-response characteristic, has the water content of 80-92%, the maximum compressive strength of 0.6-0.8 MPa and the fracture strain of 75-85%, has the advantage of good biocompatibility, and has potential application value inthe fields of drug release, molecular devices and the like.

The invention belongs to the technical field of functional materials and particularly relates to intelligent aerogel with dual responses and adjustable response behaviors and a preparation method thereof. Transition metal disulfide compound powder is ultrasonically stripped through a natural polymer water phase, a nanosheet layer of a polymer non-covalent bond modified transition metal disulfide compound is obtained, temperature-sensitive monomers and other comonomers and crosslinking agents are added to further prepare the composite aerogel of the disulfide compound nanosheet layer. The composite aerogel has excellent mechanical performance and has dual response characteristics of the far infrared response and the temperature response, and the response behaviors can be customized and adjusted. The related raw materials are natural polymers and other non-toxic and harmless reagents, water serves as an adopted solvent, the preparation process is environmentally friendly and free of pollution, operation is easy and convenient, the production cost is low, the intelligent aerogel is expected to be industrially produced on a large scale, and the prepared intelligent aerogel has multiple functions and has potential for large-scale preparation and wide commercial application prospects.

The invention relates to a preparation method for a POSS/PDMAEMA organic/inorganic hybrid material according to a thiol-ene click chemistry method. The preparation method comprises the following steps: obtaining PDMAEMA through synthesis according to an RAFT polymerization method; taking dimethyl phenylphosphine as a catalyst, taking n-hexylamine as a reducer, and conducting a reduction reaction on a dithioester group at the tail end of PDMAEMA to generate sulfydryl; conducting thiol-Michael addition reactions on the double bonds of PDMAEMA containing sulfydryl and POSS containing ethenyl according to the thiol-ene click chemistry method to generate a POSS/PDMAEMA organic/inorganic hybrid material with a temperature/pH dual response. The preparation method has the advantages that the prepared POSS/PDMAEMA organic/inorganic hybrid material is small in size, stable in chemical bond, and uniform in particle diameter; due to a click reaction to PDMAEMA, the hydrophilic performance of POSS is effectively improved; in a water solution, the POSS/PDMAEMA organic/inorganic hybrid material is excellent in temperature sensibility and pH sensibility; due to a special structure and the stimulus response performance, the POSS/PDMAEMA organic/inorganic hybrid material is a new-generation environment-friendly new material product, and can be applied to drug carrying, targeted release, metal ion recovery, environmental pollutant adsorption and other fields.

The present invention features compositions in which nano-carriers are synthesized with polymers that respond to lower pH and/or ROS by being degraded. The compositions may be utilized to selectively deliver payloads within patients by responding to lower pH and/or ROS at localities within the patient. The present invention also features methods of synthesizing nano-carriers that are degraded by lower pH and/or ROS.

The invention discloses an electrochromism-thermochromism dual-response intelligent energy saving device and a preparation method thereof; the electrochromism-thermochromism dual-response intelligent energy saving device comprises a top conductive substrate, electrolyte, a composite film, and a bottom conductive substrate arranged in sequence from top to bottom; an energy saving window introduces the electrochromism features so as to further improve regulating ability on solar energy, and the window body color can be changed by controlling voltage; the device combines electrochromism visible light waveband with thermochromism near infrared waveband regulating features, has higher solar energy regulating ability and color regulating ability when compared with a VO2 thermochromism film, has better infrared regulating ability when compared with electrochromism unit, thus providing substantial application potential in the intelligent energy saving door and window field.

The invention discloses a dual-response multiple-medicine delivery system based on cyclodextrin. Firstly, through the action of a donor and a receptor, a macrocyclic molecule cyclodextrin serving as a host and a molecule ferrocene group serving as a guest form a self-inclusion complex; the dissociation and the inclusion of the host to the guest can be realized by utilizing redox regulation and control; the effect that a micromolecular medicine is subjected to adsorption-release through a cavity of the cyclodextrin is realized; secondly, a carbon chain containing an acetal group is introduced to connect a derivative of the cyclodextrin and a silicon dioxide microsphere; in an acid environment, an acetal bond is ruptured; the derivative of the cyclodextrin is quitted; a macromolecule is further released. The medicine delivery system provided by the invention has the characteristics of redox and dual response in the acid environment, moreover, can be used for seriatim or synchronously releasing medicine molecules in different sizes, can be used for controlling administration time, a position and a dosage, and has a favorable application prospect.

The invention discloses injectable hydrogel as well as a preparation method and application thereof. The hydrogel comprises a hyaluronic acid derivative HA-ADH modified by hydrazide groups, an aldehyde bi-functionalized hyaluronic acid derivative A-HA-Dop modified by catechol in a side chain as well as an aldehyde group terminated polyoxyethylene-polypropylene oxide-polyoxyethylene triblock copolymer A-PEO-PPO-PEO-A. On one hand, the aldehyde group terminated A-PEO-PPO-PEO-A can be self-assembled into micelle, and a first network of hydrogel can be constructed by use of the characteristic of thermosensitive sol-gel conversion; and on the other hand, aldehyde groups on the surface of the A-PEO-PPO-PEO-A micelle and aldehyde groups on the A-HA-Dop can form acylhydrazone bonds with hydrazidegroups on the HA-ADH in a physiological environment to construct second and third crosslinked networks of hydrogel. By physical acting force and reversible dynamic covalent bond acting force, the injectable multi-network crosslinked hydrogel (HA-Dop/PF) which has dual response to pH and temperature and is rapid in self-healing, high in stability, high in adhesion and easy to extend and compress isobtained, and the hydrogel can be applied to biomedicine fields of tissue repair materials and drug controlled release.

The invention provides an amphiphilic block copolymer having folate-targeted pH-reduction dual-response and antineoplastic activity and preparation as well as application thereof; through RAFT polymerization, a functionalized disulfide monomer, methoxy polyethylene glycol responding by acid stimulation and functionalized folic acid form a macromolecular block copolymer, i.e. a disulfide monomer-acidity PEG-folic acid copolymer, being good in biocompatibility. The copolymer has pH and reduction dual stimulus-response, and is provided with a folic acid active targeting polymer drug carrying micelle, and can effectively release adriamycin amycin at a target site. The micelle with intelligent responsibility has low cytotoxicity, is biodegradable, has a proper drug carrying level, and can promote a great quantity of drugs to be more quickly accumulated at a tumor tissue part, thus effects in acidic cytoplasm and between cytoplasm and cell nuclei with high reducibility are achieved, and therefore the amphiphilic block copolymer as a drug carrier has a good application prospect in preparing antineoplastic drugs.

The invention relates to a targeted pH-GSH dual-response multifunctional nano-vesicle drug loading system. By using cystamine functionalized column [5] aromatic hydrocarbon with pH-GSH dual responsiveness as a host molecule and using a pyridinium modified galactose derivative as a guest molecule, glycosyl-functionalized column [5] aromatic hydrocarbon amphiphilic molecule is prepared through the host-guest interaction; nano-vesicle is formed in a solution through hydrophilic and hydrophobic effect; and an anti-cancer drug is encapsulated in the vesicle cavity so as to construct the targeted pH-GSH dual-response multifunctional nano-vesicle drug loading system. As the surface of vesicle contains galactosyl, biocompatibility of the system can be remarkably raised. Meanwhile, galactosyl can interact with specific galactose binding protein overexpressed on the surface of hepatoma carcinoma cell to realize targeted selective access to cancer cell so as to rapidly release an anti-cancer drugin the cancer cell and raise lethality of cancer cell.

Silica nanocarriers hybridized with superparamagnetic iron oxide nanoparticles (“SPIONs”) and curcumin through equilibrium or enforced adsorption technique. Methods for dual delivery of SPIONs and curcumin to a target for diagnosis or therapy, for example, for SPION-based magnetic resonance imaging or for targeted delivery of curcumin to a cell or tissue. The technique can be extend to co-precipitation of mixed metal oxide involving Ni, Mn, Co and Cu oxide. The calcination temperature can be varied from 500-900° C. The nanocombination is functionalized with chitosan, polyacrylic acid, PLGA or another agent to increase its biocompatibility in vivo.

The invention discloses a selenium-containing surfactant having pH and redox double-coincidence switch response and belongs to the technical field of the daily chemical industry. The selenium-containing surfactant is a benzyl selenoalkyl fatty acid salt and has the advantages of simple preparation method, mild synthesis conditions, no special equipment requirement, low energy consumption, easy availability of raw materials and no brominated carboxylate in the product. The selenium-containing surfactant has high surface activity and has excellent foaming and foam stabilization properties. The selenium-containing surfactant has a hydrophilic group similar to a hydrophilic group of the common fatty acid salt surfactant and has low skin irritation. The selenium-containing surfactant has unique pH and redox dual-response properties, excellent antioxidant properties and free radical scavenging ability, and low cytotoxicity and aquatic organism acute toxicity.

The invention relates to a micron-sized protease-sensitive near-infrared fluorescent light and magnetism dual-response micro-capsule. The micro-capsule is divided into an outer layer, a middle layer and an inner layer which are compactly combined; the outer layer comprises polymer molecules provided with electronegative functional groups and coated on the middle layer; the middle layer is a capsule wall of the micro-capsule, which is formed by wrapping and hybridizing a protease-sensitive positive ion peptide chain and magnetic nanoparticles; near-infrared fluorescent molecules and fluorescent quenching molecules are enveloped in the capsule wall; the inner layer is a capsule cavity of the micro-capsule; and the capsule cavity comprises one or a plurality of cavities which are separated by protease-sensitive positive ion peptide chain molecules. In tissues without specific proteases, real-time development and track of the micro-capsule can be finished through MRI (Magnetic Resonance Imaging) development enhancement; when reaching to tissues with specific proteases, the micro-capsule disintegrates and sends near-infrared fluorescent light, and meanwhile, MRI development is weakened; and therefore, the function of double targeted development of the micro-capsule is realized.

The invention relates to a preparation method of a pH and oxidation dual-responsive injectable supramolecular intelligent hydrogel. The hydrogel involved in the invention is composed of dual response method for preparing injectable supramolecular intelligent hydrogels. The hydrogel of the invention is composed of double-selenium containing multiblock polyether polyurethane, alpha-cyclodextrin, a loaded drug and water. The preparation process consists of: firstly introducing a double-selenium bond to a polyurethane main chain with good biocompatibility and pH sensitivity, then loading a hydrophobic drug at the same time of self-assembly into nanoparticles, finally introducing alpha-cyclodextrin molecules into the nanoparticle solution and letting the alpha-cyclodextrin molecules interpenetrate to a polyethylene glycol chain so as to obtain the supramolecular intelligent hydrogel, and loading the hydrophobic drug at the same time. The hydrogel has shear thinning property, and can be easily injected, is sensitive to pH and oxidation reduction environment, also can be oxidized and degraded through the introduced double-selenium bond, and has good application prospect in the biomedicine field as a common controlled-release carrier of hydrophilic and hydrophobic drugs.

The invention relates to a preparation method of a folic acid-modified molybdenum disulfide-coated periodic mesoporous organic silicone nano drug-loaded compound. The preparation method comprises the following steps: dispersing cetyltrimethylammonium bromide in a solvent; adding TEOS and TESPTS into the mixed liquid for reacting to obtain PMOs; modifying the surface of the PMOs with sulfydryl to obtain PMOs-SH; mixing the obtained product with doxorubicin DOX to obtain PMOs-DOX; preparing LA-PEI and modifying to molybdenum disulfide with the LA-PEI to obtain MoS2-LA-PEI; mixing the obtained product with PMOs-DOX, and performing ultrasonic treatment; then reacting the product with folic acid-modified bovine serum albumin BSA to obtain a product PMOs-DOX@MoS2-PEI-BSA-FA. The method provided by the invention is simple; the product realizes dual-response conveying for pH and illumination, has relatively high biocompatibility and is expected to be applied to tumor targeting and synergistic treatment.

The invention discloses a dual-response magnetic nano particle with fluorescence and a preparation method thereof, belonging to the technical field of functional polymer materials. An existing response magnetic nano particle is smaller in response range and is incapable of tracing mark. A chemical expression formula of the magnetic nano particle is Fe3O4@M(III)-(PNIPAMm-b-PAzoMAn)-TTA (PNIPAM (Poly(N-isopropylacrylamide) and TTA (thenoyltrifluoroacetone), wherein M is Eu<3+>, Tb<3+>, Sm<3+> or Er<3+>, m is equal to 42-132, and n is equal to 5-20. AzoMA and NIPAM (N-isopropylacrylamide) are polymerized to an RAFT (Reversible Addition-Fragmentation chain Transfer) chain transfer agent through an RAFT free radical polymerization method, and M(III)-(PNIPAMm-b-PAzoMAn)-TTA is obtained through a coordination reaction, and then is modified to the surface of a ferriferrous oxide nano particle through an esterification reaction. The dual-response magnetic nano particle is capable of carrying out magnetic separation under the control of the temperature and the light, and has a potential application value in the aspects of biological marking, imaging, artificial muscle and the like.

The invention provides a photonic crystal nano-composite gel membrane with temperature/humidity dual responses. 2D colloidal photonic crystals are prepared with soap-free emulsion polymerization and needle tip flow methods, a nano-composite hydrogel pre-polymerization solution is prepared through introduction of inorganic nanoparticles as a physical crosslinking agent, finally, the 2D colloidal photonic crystals and the nano-composite hydrogel pre-polymerization solution are compounded, and the photonic crystal nano-composite gel membrane with the temperature/humidity dual responses is prepared; the photonic crystal gel membrane serving as a sensor realizes effects of fast response, high toughness and excellent optical signal resolution and achieves the purpose of rapidly detecting outsidetemperature/humidity change through color change. Preparation of the gel membrane comprises steps as follows: (1), synthesis of mono-disperse latex particles; (2), preparation of the 2D colloidal photonic crystals with the needle tip method; (3), preparation of the nano-composite hydrogel pre-polymerization solution; (4), preparation of the responsive photonic crystal nano-composite gel membrane.The preparation method is simple and convenient to operate, and the photonic crystal nano-composite gel membrane is high in color change visibility, optical signal resolution and response rate and can be applied to fast detection of temperature/humidity, metal ions, toxicants, biochemical reagents, environmental pollutants and the like.