Passive direct methanol fuel cells acting as fully autonomous electrochemical biosensors: Application to sarcosine detection

• Autor(a) principal: Silva Ferreira, Nadia
• Data de Publicação: 2022
• Outros Autores: Carneiro, Liliana P.T, Viezzer, Christian, Almeida, Maria J.T., Marques, Ana C., Pinto, Alexandra M.F.R., Fortunato, Elvira, Ferreira Sales, Maria Goreti
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/21879
• topic: Passive direct methanol fuel cell; Molecularly imprinted polymer; Electrochromic cell; Colour display; Sarcosine; Cancer biomarker

This work describes an innovative electrochemical biosensor that advances its autonomy toward an equipment-free design. The biosensor is powered by a passive direct methanol fuel cell (DMFC) and signals the response via an electrochromic display. Briefly, the anode side of the DMFC power source was modified with a biosensor layer developed using molecularly imprinted polymer (MIP) technology to detect sarcosine (an amino acid derivative that is a potential cancer biomarker). The biosensor layer was anchored on the surface of the anode carbon electrode (carbon black with Pt/Ru, 40:20). This was done by bulk radical polymerization with acrylamide, bis-acrylamide, and vinyl phosphonic acid. This layer selectively interacted with sarcosine when integrated into the passive DMFC (single or multiple, in a stack of 4), which acted as a transducer element in a concentration-dependent process. Serial assembly of a stack of hybrid DMFC/biosensor devices triggered an external electrochromic cell (EC) that produced a colour change. Calibrations showed a concentration-dependent sarcosine response from 3.2 to 2000 µM, which is compatible with the concentration of sarcosine in the blood of prostate cancer patients. The final DMFC/biosensor-EC platform showed a colour change perceptible to the naked eye in the presence of increasing sarcosine concentrations. This colour change was controlled by the DMFC operation, making this approach a self-controlled and self-signalling device. Overall, this approach is a proof-of-concept for a fully autonomous biosensor powered by a chemical fuel. This simple and low-cost approach offers the potential to be deployed anywhere and is particularly suitable for point-of-care (POC) analysis.