Quantum-Dot-Based Photoelectrochemical Biosensors: Principles, Fabrication, and Applications

Quantum-dot-based photoelectrochemical (Q-dot PEC) biosensors shows exceptional characteristics features: they have high sensitivity, are easy to operate, do not require expensive instruments, are low cost, have a wide linearity range, achieve rapid detection, and need low background current. The Q-dots immobilized on the conducting electrode act as a working electrode, on platinum act as a counter electrode and silver/silver chloride, and on saturated KCl act as reference electrode in q-dot-based PEC biosensor, whereas Q-dots commonly act as light-sensitized material and create electron-hole pairs and enhance the amplitude of the output signal. Q-dots have a tunable band gap and tune the band gap energy by modifying the size of Q-dots. Tunable band gap materials could be tuned to harvest a wide range of light including ultraviolet, visible, and the infrared region of the spectrum to switch the sensor to higher sensitivity. In this chapter we reviewed the general principles of Q-dot-based PEC biosensors, assembling methods, and progress of their recent applications.