Modern-day cell-phone cameras advance in quality and low light sensitivity due to back-illuminated CMOS sensors and noise removal software pre-processing of the captured images. These cameras’ outstanding quality and sensitivity can also act as sensitive light detectors, such as handheld cell-phone-sized Raman spectrometer, for various types of sensing.
The cell-phone-based Raman and emission spectral detector, coupled to a diffraction grating and cell-phone camera system, provides means for detecting, recording, and identifying chemicals, drugs, and biological molecules in situ through their Raman and fluorescence spectra. The cell-phone spectrometer system recorded Raman spectra from various chemicals and biological molecules, including the resonance-enhanced Raman spectra of carrots and bacteria.
The scientists simplified the excitation and emission geometry of the cell-phone Raman spectroscopic system by lowering the count of optical components that record the spectra and integrating them into a cell-phone. Future cell-phones can identify chemical impurities and pathogens in situ within minutes, using this inexpensive yet accurate pocket Raman system.