Quantum Optical Sensors for Biomedical Applications

Quantum optical sensors have evolved into a powerful class of analytical instruments for biological applications, offering unmatched sensitivity, selectivity, and real-time monitoring capabilities. This chapter provides a comprehensive analysis of the principles, design approaches, and applications of quantum nanomaterials (QDs) in optical biosensing platforms. The production strategies of QDs, including colloidal, sol-gel, solvothermal, and plasma-assisted procedures, are analyzed in relation to the improvement of optical performance and biocompatibility. Critical optical approaches, such as fluorescence spectroscopy, Raman spectroscopy, and bioimaging techniques, are thoroughly analyzed, emphasizing their integration with nanostructures to enhance diagnostic effectiveness. The unique size-dependent optical properties, biocompatibility, and tunability of QDs enable multiplexed biomolecule detection, real-time cellular imaging, and targeted drug delivery. Recent breakthroughs in surface-enhanced Raman spectroscopy (SERS), fluorescent nanosensors for neurotransmitter detection, and in vivo imaging employing carbon-based and metal-based nanoprobes are highlighted. Notwithstanding significant progress, the chapter also addresses persistent challenges such as reproducibility, toxicity, matrix interference, and regulatory limitations. This chapter emphasizes the considerable potential of quantum optical sensors in improving biological diagnostics and personalized healthcare.