Bacteriorhodopsin (bR) is a light-driven proton pump protein from Halobacterium salinarum. It is a highly stable biomolecule that is important for bioelectronic devices. Its unique photocycle helps move protons, turning light energy into chemical energy. bR stays stable across a wide range of temperatures, pH levels, and high salt concentrations. Applications include photochemical uses, such as optical volumetric memories and security inks, and photoelectric uses, such as motion biosensors, X-ray sensors, photovoltaic cells, immunosensors, and artificial retinal prostheses. Notably, peptide-coated bR-based photoelectric biosensors have high sensitivity and specificity for detecting rheumatoid arthritis. The functionality of these devices depends on Transimpedance Amplifiers (TIAs). These often use half-shared operational amplifier designs. This design can cut down the silicon area and power consumption by nearly 50% for measuring pico-currents. Challenges in measuring pico-currents arise from various noise sources. Techniques like guarding, shielding, and using CMOS op-amps can help reduce these issues. The chopper technique also improves noise reduction in TIAs. Computational simulations, such as those done with COMSOL, are vital for modeling. Different methods for preparing bR layers, like Langmuir-Blodgett, are also important for achieving optimal device performance. Future work will focus on improving scalability and making devices more suitable for human use.