title: Exploiting metal-organic coordination polymers as highly efficient immobilization matrixes of enzymes for sensitive electrochemical biosensing.
abstract: We report on the exploitation of metal-organic coordination polymers (MOCPs) as new and efficient matrixes to immobilize enzymes for amperometric biosensing of glucose or phenols. A ligand, 2,5-dimercapto-1,3,4-thiadiazole (DMcT), two metallic salts, NaAuCl(4) and Na(2)PtCl(6), and two enzymes, glucose oxidase (GOx) and tyrosinase, are used to demonstrate the novel concept. Briefly, one of the metallic salts is added into an aqueous suspension containing DMcT and one of the enzymes to trigger the metal-organic coordination reaction, and the yielded MOCPs-enzyme biocomposite (MEBC) is then cast-coated on an Au electrode for biosensing. The aqueous-phase coordination polymerization reactions of the metallic ions with DMcT are studied by visual inspection as well as some spectroscopic, microscopic, and electrochemical methods. The thus-prepared glucose and phenolic biosensors perform better in analytical performance (such as sensitivity and limit of detection) than those prepared by the conventional chemical and/or electrochemical polymerization methods and most of the reported analogous biosensors, as a result of the improved enzyme load/activity and mass-transfer efficiency after using the MOCPs materials with high adsorption/encapsulation capability and unique porous structure. For instance, the detection limit for catechol is as low as 0.2 nM here, being order(s) lower than those of most of the reported analogues. The enzyme electrode was also used to determine catachol in real samples with satisfactory results. The emerging MOCPs materials and the suggested aqueous-phase preparation strategy may find wide applications in the fields of bioanalysis, biocatalysis, and environmental monitoring.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Fu
authors.forename: Penghao
authors.initials: P
authors.lastname: Li
authors.forename: Lijuan
authors.initials: L
authors.lastname: Bu
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Qingji
authors.initials: Q
authors.lastname: Xie
authors.forename: Jinhua
authors.initials: J
authors.lastname: Chen
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002396:Catechols / Q000032:analysis; D055664:Electrochemical Techniques; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase / Q000378:metabolism*; D006046:Gold / Q000737:chemistry; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D010636:Phenols / Q000032:analysis; D010984:Platinum / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D013830:Thiadiazoles / Q000737:chemistry
chemical_list: D002396:Catechols; D004800:Enzymes, Immobilized; D010636:Phenols; D011108:Polymers; D012492:Salts; D013830:Thiadiazoles; C012291:2,5-dimercapto-1,3,4-thiadiazole; D010984:Platinum; D006046:Gold; D005949:Glucose Oxidase; D014442:Monophenol Monooxygenase; D005947:Glucose