Complementary Metal Oxide Semiconductor-Based Optical Detection System for Fluidic Cellular Medium pH Quantification

• DOI: 10.3390/photonics11121130
• Publication Date: 2024-12-02T08:50:57Z
• Authors: André A. Santos; Gabriel M. Ferreira; Paulo J. Sousa; Patrícia C. Sousa; Susana O. Catarino; Graça Minas
• Keywords: Fluidics

Accurate pH sensing is essential for the effective physiological control of culture media in organ-on-a-chip (OoC) systems. This work proposes a miniaturized optical detection system, based on transmittance, level quantification EGM™-2 Endothelial Cell Growth Medium-2 BulletKit™ medium. Firstly, using commercial spectrophotometric setup, set wavelengths (500, 560, and 600 nm) was selected, as these assure distinctive slope variations different levels. Then, current-to-frequency converter, low-power Schmitt trigger model with voltage enhancer, proposed readout electronics simulated Cadence Tools UMC L180 MM/RF technology. A resolution 0.002 nA achieved linear range 30 pA to 3800 nA. system composed CMOS n-well/p-substrate photodiode polydimethilsiloxane (PDMS) microchannel substrate experimentally tested. For from 6.6 6.2, results clearly demonstrate magnitude shift signal, which becomes negative basic positive acidic media. Additionally, 500–560 nm spectral range, amplitude slopes increases both In 560–600 decreases progressively medium lowers. able quantify medium, showing potential be integrated into an device.