Combined “dual” absorption and fluorescence smartphone spectrometers

Abstract

A combined "dual" absorption and fluorescence smartphone spectrometer is demonstrated. The optical sources used in the system are the white flash LED of the smartphone and an orthogonally positioned and interchangeable UV (λ_ex=370 nm) and blue (λ_ex=450 nm) LED. The dispersive element is a low-cost, nano-imprinted diffraction grating coated with Au. Detection over a 300 nm span with 0.42 nm/pixel resolution was carried out with the camera CMOS chip. By integrating the blue and UV excitation sources into the white LED circuitry, the entire system is self-contained within a 3D printed case and powered from the smartphone battery; the design can be scaled to add further excitation sources. Using a customized app, acquisition of absorption and fluorescence spectra are demonstrated using a blue-absorbing and green-emitting pH-sensitive amino-naphthalimide-based fluorescent probe and a UV-absorbing and blue-emitting Zn²⁺-sensitive fluoro-ionophore.

Mobile Device Based Water Monitoring with Single Reference Image

“…With the help of 3D printers, smartphone spectrometer systems found wide range of colorimetric measurements application for chemical and biological analytes [3]. Some of them are water quality sensing for environment [4,5], leaf color analysis for agriculture [6], pH [7,8] and glucose [9] sensing, and peanut allergen detection [10]. Color data is mostly used in paper based sensors application where parameters from various color spaces, i.e.…”

Smartphone based optical spectrometer for diffusive reflectance spectroscopic measurement of hemoglobin

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Multimode smartphone biosensing: the transmission, reflection, and intensity spectral (TRI)-analyzer

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