A dual extension CMOS imager, also known as a High and Low Light Imager (HALLI), and peripherals for biomedical applications is presented in this thesis. The HALLI utilizes a single column parallel partitioned pixel amplifier with variable topology for the detection of both high and low light levels in the same frame. For fluorescence detection the fabrication of a low cost poly-acrylic acid (PAA) based emission filter integrated with the CMOS contact imager is introduced. An additional peripheral proposed in this research is a rail-to-rail differential difference amplifier which can be integrated as part of the imager architecture and will allow for high resolution analog-to-digital conversion using a newly developed expanding technique. The HALLI and peripherals are key components towards achieving a lab-on-a-chip device for biomedical applications.