title: Biofuel cell based self-powered sensing platform for L-cysteine detection.
abstract: L-cysteine (L-Cys) detection is of great importance because of its crucial roles in physiological and clinical diagnoses. In this study, a glucose/O2 biofuel cell (BFC) was assembled by using flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH)-based bioanode and laccase-based biocathode. Interestingly, the open circuit potential (OCP) of the BFC could be inhibited by Cu(2+) and subsequently activated by L-Cys, by which a BFC-based self-powered sensing platform for the detection of L-Cys was proposed. The FAD-GDH activity can be inhibited by Cu(2+) and, in turn, subsequent reversible activation by L-Cys because of the binding preference of L-Cys toward Cu(2+) by forming the Cu-S bond. The preferential interaction between L-Cys and Cu(2+) facilitated Cu(2+) to remove from the surface of the bioanode, and thus, the OCP of the system could be turned on. Under optimized conditions, the OCP of the BFC was systematically increased upon the addition of the L-Cys. The OCP increment (ΔOCP) was linear with the concentration of L-Cys within 20 nM to 3 μM. The proposed sensor exhibited lower detection limit of 10 nM L-Cys (S/N = 3), which is significantly lower than those values for other methods reported so far. Other amino acids and glutathione did not affect L-Cys detection. Therefore, this developed approach is sensitive, facile, cost-effective, and environmental-friendly, and could be very promising for the reliable clinically detecting of L-Cys. This work would trigger the interest of developing BFCs based self-powered sensors for practical applications.
authors.forename: Chuantao
authors.initials: C
authors.lastname: Hou
authors.affiliation: ‡University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Shuqin
authors.initials: S
authors.lastname: Fan
authors.forename: Qiaolin
authors.initials: Q
authors.lastname: Lang
authors.affiliation: ‡University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
mesh_terms: D001230:Aspergillus / Q000201:enzymology; D052160:Benzothiazoles / Q000737:chemistry; D001674:Bioelectric Energy Sources; D003300:Copper / Q000494:pharmacology; D003545:Cysteine / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D004579:Electron Transport; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005947:Glucose / Q000737:chemistry; D042843:Glucose 1-Dehydrogenase / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry; D024483:Vitamin K 3 / Q000737:chemistry
chemical_list: D052160:Benzothiazoles; D004791:Enzyme Inhibitors; D013451:Sulfonic Acids; D005182:Flavin-Adenine Dinucleotide; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D024483:Vitamin K 3; D003300:Copper; D042843:Glucose 1-Dehydrogenase; D005947:Glucose; D003545:Cysteine; D010100:Oxygen