Current reported smartphone spectrometers are only used to monitor or measure one sample at a time.
For the first time, we demonstrate a multichannel smartphone spectrometer (MSS) as an optical biosensor
that can simultaneously optical sense multiple samples. In this work, we developed a novel
method to achieve the multichannel optical spectral sensing with nanometer resolution on a smartphone.
A 3D printed cradle held the smartphone integrated with optical components. This optical sensor
performed accurate and reliable spectral measurements by optical intensity changes at specific wavelength
or optical spectral shifts. A custom smartphone multi-view App was developed to control the
optical sensing parameters and to align each sample to the corresponding channel. The captured images
were converted to the transmission spectra in the visible wavelength range from 400 nm to 700 nm with
the high resolution of 0.2521 nm per pixel. We validated the performance of this MSS via measuring the
concentrations of protein and immunoassaying a type of human cancer biomarker. Compared to the
standard laboratory instrument, the results sufficiently showed that this MSS can achieve the comparative
analysis detection limits, accuracy and sensitivity. We envision that this multichannel smartphone
optical biosensor will be useful in high-throughput point-of-care diagnostics with its minimizing
size, light weight, low cost and data transmission function