Figure 3From: Microfluidic biosensor for β-Hydroxybutyrate (βHBA) determination of subclinical ketosis diagnosis Schematic diagram of the optical biosensor. (a) Components of the optical biosensor. (b) Custom-built biosensor packaging for optical and electrical components assembly. Labels 1, 2, 3, 4 indicate the positions for mounting LED, bandpass filter, microfluidic chip and Si photodiode, respectively.Back to article page