A sensing device able to do concurrent real time detection of different kinds of chemical, biomolecule agents, or biological cells and their respective concentrations using optical principles. The sensing system can be produced at a low cost (below $1.00) and in a small size (˜1 cm3). The novel sensing system may be of great value to many industries, for example, medical, forensics, and military. The fundamental principles of this novel invention may be implemented in many variations and combinations of techniques.