ABSTRACT
Optical sensors belong to the most important types of chemical sensors that have been extensively studied in recent years for the continuous and real-time monitor ing of analytes. Depending on the origin of the optical signals, these types of sensors may be roughly classified into absorbance and luminescence-based sen sors, the latter mainly utilizing the principle of fluorescence and chemilumines cence (CL) detection. Although they offer many advantages such as high sensitiv ity, good selectivity, and fast response time, fluorescence-based sensors require an excitation light source and spectral separation of exciting and emitted light, leading to relatively sophisticated equipment producing high background signals.
