Study On Kanamycin Biosensor Based On Nucleic Acid Aptamer And Nanomaterial Signal Transduction

In recent years,food safety and public health problems caused by antibiotics abuse have attracted extensive attention.Due to its excellent bactericidal properties and affordability,kanamycin,a broad-spectrum aminoglycoside antibiotic,finds extensive applications in the fields of medical treatment,animal husbandry,and aquaculture However,owing to its comparatively narrow safety margin,excessive abuse of kanamycin will lead to the accumulation in soil,water,livestock,and dairy products,which can seriously endanger human health through the food chain,causing nephrotoxicity,ototoxicity,allergic reactions and drug resistance.Therefore,it is very necessary to detect kanamycin in food or environment sample for preventing drug abuse and guaranteeing human health.In this paper,the detection methods of kanamycin based on nucleic acid aptamer and nanomaterial signal transduction were studied.The details are as follows:(1)Correct the errors of the traditional kanamycin colorimetric detection theory,studied the interaction between kanamycin and gold nanoparticles(AuNPs)and the effects of the specific aptamer adsorption,and propose a new alternative adsorption mechanismIn this work,we first studied the adsorption of kanamycin on AuNPs and performed a comprehensive analysis of the interaction between kanamycin and AuNPs and the effects of the specific aptamer adsorption through the UV-visible absorption spectrum(UV-vis),transmission electron microscope(TEM)and surface-enhanced raman spectrum(SERS).Our results support a new alternative view that kanamycin can directly induce the aggregation of aptamer-wrapped AuNPs,attributed to the coadsorption of kanamycin and aptamer on the surface of AuNPs.Thus,a novel strategy for detecting kanamycin based on target-induced AuNPs colorimetric sensing was developed,which avoiding the tedious and unnecessary salt-induced process.Under optimum conditions,the proposed colorimetric sensing assay showed a good performance for kanamycin in linear range of 10.0 nM-4.0 μM with the detection limit was 4.0 nM.The whole detection process could be completed within 5 min.At the same time,the proposed method showed satisfactory sensitivity and specificity in practical application with recoveries in the range of 86.22-109.89%.The results indicate that target-induced AuNPs colorimetric sensing coupled with aptamers for the direct detection of kanamycin is simple,rapid and high-sensitivity,has the promising potential applications in the fields of food safety and environmental monitoring.This chapter not only develops a new method for simple and rapid detection of kanamycin,but also corrects the mistakes of traditional views,which will cause most researchers to rethink the principle of gold nanocolorimetric detection of kanamycin(2)In order to further lower the detection limit of kanamycin,the chemiluminescence signal of luminol-H2O2 catalyzed by graphene oxide(GO)was directly captured by building a low-light measuring instrument,avoiding the tedious modification and signal amplification process.Compared with the targeted induced AuNPs colorimetric sensing method,the detection limit of kanamycin was successfully reduced by 2 orders of magnitudeGO,as a two-dimensional nanomaterial,can effectively catalyze the decomposition reaction of H2O2 and exhibit a catalytic activity due to the peroxidaselike catalytic activity.In addition,compared with traditional peroxidases,graphene oxide has high catalytic activity and stronger stability,which makes it a promising enzyme mimic.However,in practical applications,GO requires the surface modification to enhance the enzymatic activity of GO,which makes the procedure tedious.In our work,we developed a new simple and sensitive kanamycin trace chemiluminescence detection method by combining the specific recognition ability of the aptamer to kanamycin and the properties of GO bionic simulation enzyme.The chemiluminescence signal enhanced by GO can sensitively distinguish the conformational change of the aptamer,which induced by the kanamycin.The chemiluminescence detetion process was automated based on the ultra weak luminescence analyzer that we built,and the limit of detection was up to 20 pM,and the sensitivity is comparable to that of chromatography.Because of the simulated enzyme properties of GO itself,the signal amplification of luminol-H2O2 system is realized,and the salt induction process is avoided,making the whole detection process more simple and convenient.Furthermore,the sensitivity of the system was enhanced through the utilization of chemiluminescence analysis.To validate the reliability of the sensor in practical application,tests were conducted on food samples as well as samples from the actual environment.