title: Self-assembled CNTs/CdS/dehydrogenase hybrid-based amperometric biosensor triggered by photovoltaic effect.
abstract: A novel multi-components hybrid material, self-assembled quantum dots (CdS) and glutamate dehydrogenase (GDH) onto multiwall carbon nanotubes (CNTs), was designed for amperometric biosensing system. The zeta-potential and transmission electron microscopy (TEM) analyses confirmed the uniform growth of the CdS/GDH onto carboxyl-functionalized CNTs. Compared with the single CdS, the resulting hybrid material showed more efficient generation of photocurrent upon illumination. The incident light excites CdS and generates charge carriers, and then CNTs facilitates the charge transfer. For dehydrogenase-based biosensor, normally, the cofactor of beta-nicotinamide adenine dinucleotide (NAD(+)) or beta-nicotinamide adenine dinucleotide phosphate (NADP(+)) is necessary. Furthermore, we found the photovoltaic effect of CNTs/CdS/GDH can trigger the dehydrogenase enzymatic reaction in the absence of the NAD(+) or NADP(+) cofactors. The electrochemical experiment results also demonstrate that the cofactor-independent dehydrogenase biosensing system had series attractive characteristics, such as a good sensitivity (11.9 nA/microM), lower detection limit (up to 50 nM), an acceptable reproducibility and stability. These studies aid in understanding the combination of the semiconductor nanohybrids (CNTs/QDs, etc.) and biomolecules (enzymes, etc.), which has potential for the applications in biosensor, biofuel cell, biomedical and other bioelectronics field.
authors.affiliation: Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Longhua
authors.initials: L
authors.lastname: Tang
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yang
authors.forename: Jinjie
authors.initials: J
authors.lastname: Sun
authors.forename: Chunzhong
authors.initials: C
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D019187:Cadmium Compounds / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005969:Glutamate Dehydrogenase / Q000737:chemistry*; D018698:Glutamic Acid / Q000032:analysis*; D036103:Nanotechnology / Q000295:instrumentation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010777:Photochemistry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013440:Sulfides / Q000737:chemistry*; D018511:Systems Integration
chemical_list: D019187:Cadmium Compounds; D037742:Nanotubes, Carbon; D013440:Sulfides; C034939:cadmium sulfide; D018698:Glutamic Acid; D005969:Glutamate Dehydrogenase