title: A Novel Photoelectrochemical Biosensor for Tyrosinase and Thrombin Detection.
abstract: A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs)-modified indium-tin oxide (ITO) electrode through electrostatic attraction to construct the photoelectrochemical biosensor. The tyrosinase target can catalyze the oxidization of tyrosine by oxygen into ortho-benzoquinone residues, which results in a decrease in the sensor photocurrent. Subsequently, the cleavage site could be recognized and cut off by another thrombin target, restoring the sensor photocurrent. The decrease or increase of photocurrent in the sensor enables us to assay tyrosinase and thrombin. Thus, the detection of tyrosinase and thrombin can be achieved in the linear range from 2.6 to 32 μg/mL and from 4.5 to 100 μg/mL with detection limits of 1.5 μg/mL and 1.9 μg/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates.
authors.affiliation: Anhui Key Laboratory of Chem-Biosensing, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. jiexchen@163.com.|Departement of Chemistry, Wannan Medical College, Wuhu 241002, China. jiexchen@163.com.
authors.forename: Jiexia
authors.initials: J
authors.lastname: Chen
authors.affiliation: Anhui Key Laboratory of Chem-Biosensing, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. lyffxk@126.com.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Anhui Key Laboratory of Chem-Biosensing, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China. gczhao@mail.ahnu.edu.cn.
authors.forename: Guang-Chao
authors.initials: GC
authors.lastname: Zhao
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D002417:Cattle; D055664:Electrochemical Techniques / Q000379:methods*; D055767:Immobilized Proteins / Q000737:chemistry; D057230:Limit of Detection; D014442:Monophenol Monooxygenase / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry; D012710:Serum Albumin, Bovine; D013691:Tellurium / Q000737:chemistry; D013917:Thrombin / Q000032:analysis*
chemical_list: D019187:Cadmium Compounds; D055767:Immobilized Proteins; D012710:Serum Albumin, Bovine; D014442:Monophenol Monooxygenase; D013917:Thrombin; D013691:Tellurium; C028337:cadmium telluride
keywords: peptide; photoelectrochemical biosensor; thrombin; tyrosinase