A paper-based microfluidic biosensor integrating zinc oxide nanowires for electrochemical glucose detection

• DOI: 10.1038/micronano.2015.14
• Publication Date: 2015-11-18T09:39:28Z
• Authors: Xiao Li; Chen Zhao; Xinyu Liu
• Keywords: Glucose oxidase

Abstract This paper reports an electrochemical microfluidic paper-based analytical device (EμPAD) for glucose detection, featuring a highly sensitive working electrode (WE) decorated with zinc oxide nanowires (ZnO NWs). In addition to the common features of μPADs, such as their low costs, high portability/disposability, and ease operation, reported EμPAD has three further advantages. (i) It provides higher sensitivity lower limit detection (LOD) than previously μPADs because surface-to-volume ratio enzyme-capturing efficiency ZnO NWs. (ii) does not need any light-sensitive electron mediator (as is usually required in enzymatic sensing), which leads enhanced biosensing stability. (iii) The NWs are directly synthesized on substrate via low-temperature hydrothermal growth, representing simple, low-cost, consistent, mass-producible process. To achieve superior performance, on-chip stored enzyme (glucose oxidase) dose assay incubation time tuned. More importantly, critical design parameters EμPAD, including WE area ZnO-NW growth level, adjusted yield tunable ranges LOD. highest that we have achieved 8.24 μA·mM −1 ·cm −2 , corresponding LOD 59.5 μM. By choosing right combination parameters, constructed EμPADs cover range clinically relevant concentrations (0−15 mM) fully calibrated these devices using spiked phosphate-buffered saline human serum. We believe approach integrating could be well utilized many other designs facile inexpensive paradigm enhancing performance.