PROJECT TITLE :
A Pseudobipolar Junction Transistor for a Sensitive Optical Detection of Biomolecules
A new optical sensor system, known as the pseudo-bipolar junction transistor (BJT) optical measurement system (PBOS), based on a pseudo-BVceo of the BJT is proposed by adding a back-to-back connection of a laser diode (LD) (or an LED) and a p-i-n photodiode (PD) in the standard optical measurement system operated within the photoconductive mode. A back-to-back connection of two optoelectronic devices and illumination of the light from the LD to the PD generates an optical current gain within the PD. It's the same as the current flowing mechanism within the BJT beneath the bottom open condition, in which the forward emitter–base junction current generates an electrical current gain in the bottom–collector junction. Just like the negative differential resistance (NDR) once BVceo of the BJT, the NDR is observed in the PBOS. Operating the PBOS within the NDR region, the system can offer a lot of higher sensitivity and lower limit of detection compared with the conventional optical measurement system within the photoconductive mode with a p-i-n PD. We show a mathematical model of the sensitivity of the PBOS to the transmittance of the optical path and our initial information for glucose detection as a potential application of the system.
Did you like this research project?
To get this research project Guidelines, Training and Code... Click Here