No abstract

No abstract

No abstract

This paper establishes a membraneless, co-laminar flow-based approach to develop a cost-effective microfluidic paper-based analytical device for enzymatic biofuel cell ( PAD-EBFC). The developed PAD-EBFC supporting the self-capillary fluid transport action consists of Y-shaped paper microchannel with the fuel (glucose) and oxidant (O) streaming in parallel over carbon nanotube-based bucky paper electrodes modified with biocompatible electrocatalytic enzymes, such as glucose oxidase and laccase without any additional redox cofactor. The electrochemical performance for the modified bioelectrodes, i.e., electrocatalytic oxidation and reduction reaction, was carried out using linear sweep voltammetry, cyclic voltammetry, and open circuit potential. The overall performance of PAD-EBFC was evaluated using the polarization studies. Subsequently, the catalytic activity of enzymes on the electrode surface was validated by the scanning electron microscope. This simple and portable PAD-EBFC can generate the maximum power density to the order of /cm ( /cm) at 0.505 V over prolonged durations of around 50 h. Hence, the presented PAD-EBFC shows good power density and stability, leading to its strong potential to power miniaturized microelectronics devices and sensors.

The integration of multimode ion-exchange waveguides and etched microchannels in glass biochips is described. The waveguides were used to carry laser light to specific points in the channels for the detection of fluorescent microparticles. Anomalous etching was observed at the intersections of the waveguides and the microchannels resulting in the partial etching of the waveguides to form side-channels to the main channels. When filled with fluid, these side-channels have a lower index of refraction than the surrounding waveguides causing the laser light to illuminate the microchannel in two places. It is demonstrated how the double-peaked signal from a passing fluorescent microparticle can be used to directly determine the velocity of the liquid in microchannels.