Towards timely Alzheimer diagnosis: A self-powered amperometric biosensor for the neurotransmitter acetylcholine.
Serious brain disorders, such as the Alzheimer's Disease (AD), are associated with a marked drop in the levels of important neurotransmitters, such as acetylcholine (ACh). Real time monitoring of such biomarkers can therefore play a critical role in enhancing AD therapies by allowing timely diagnosis, verifications of treatment effectiveness, and developments of new medicines. In this study, we present the first acetylcholine/oxygen hybrid enzymatic fuel cell for the self-powered on site detection of ACh in plasma, which is based on the combination of an enzymatic anode with a Pt cathode. Firstly, an effective acetylcholinesterase immobilized electrode was developed and its electrochemical performance evaluated. Highly porous gold was used as the electrode material, and the enzyme was immobilized via a one step rapid and simple procedure that does not require the use of harsh chemicals or any electrode/enzyme pre-treatments. The resulting enzymatic electrode was subsequently used as the anode of a miniature flow-through membrane-less fuel cell and showed excellent response to varying concentrations of ACh. The peak power generated by the fuel cell was 4nW at a voltage of 260mV and with a current density of 9μAcm-2. The limit of detection of the fuel cell sensor was 10μM, with an average response time as short as 3min. These exciting results open new horizons for point-of-care Alzheimer diagnosis and provide an attractive potential alternative to established methods that require laborious and time-consuming sample treatments and expensive instruments.
BioMark-CINTESIS/ISEP, School of Engineering, Polytechnic Institute of Porto, Portugal.
Felismina T C
FTC
Moreira
BioMark-CINTESIS/ISEP, School of Engineering, Polytechnic Institute of Porto, Portugal.
M Goreti F
MGF
Sale
University of Bath, Department of Chemical Engineering, Bath BA2 7AY, UK. Electronic address: M.Di.Lorenzo@bath.ac.uk.
Mirella
M
Di Lorenzo
D000109:Acetylcholine / Q000097:blood* / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism*; D000544:Alzheimer Disease / Q000097:blood / Q000175:diagnosis* / Q000378:metabolism; D001674:Bioelectric Energy Sources; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000378:metabolism*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D010984:Platinum / Q000737:chemistry; D019095:Point-of-Care Systems; D016062:Porosity
D015415:Biomarkers; D004800:Enzymes, Immobilized; D010984:Platinum; D006046:Gold; D000110:Acetylcholinesterase; D000109:Acetylcholine
Acetylcholine; Acetylcholinesterase; Alzheimer; Enzymatic fuel cell; Highly porous gold