Compact Poly/Monochromatic Colorimetric Sensing System With Integrated Microfluidic Sampler

This work describes a new hybrid colorimetric sensor instrument that combines a monochromator and a polychromator to achieve high spectral resolution in a reduced size, at low cost and ease of use. The system design uses an integrated subsystem approach with optical spectrometry, microfluidic micromixing, and microsampling components, emphasizing autonomous sample manipulation and analysis. A comprehensive description of the sensor's design is presented, detailing the optical, microfluidic, electronic, and mechanical aspects. This compact and autonomous sensor heralds promising applications across chemistry, with a comparable accuracy to that of commercial instruments. The reported theoretical resolution of the polychromator is 0.24 nm while the measured resolving power is 100 for a bandwidth of 118 nm centered at 557.7 nm. The monochromator has a 16-bit resolution for a bandpass of 10 nm. The average difference between the measured absorbance curves by a Cary-7000 commercial spectrometer and our instrument is 14.55 (A<middle dot> lambda).