Multifunctional Webcam Spectrophotometer for Performing Analytical Determination and Measurements of Emission, Absorption, and Fluorescence Spectra

Abstract

This paper reports the development and application of a low-cost multifunctional webcam spectrophotometer for the conduct of molecular absorption and fluorometric measurements. The equipment, which costs approximately US$20 to be fabricated, consists of a webcam, a diffraction grating, and a slit, all positioned inside an MDF box. Spectral measurements were carried out using the multifunctional equipment with the aid of a free software. The equipment was found to be suitable for conducting qualitative and quantitative analyses of fluorescence, absorption, and emission spectra and for analytical determinations in the spectral range of 380.00 to 1000.00 nm with 0.8 nm resolution. By simply changing the light radiation source, the equipment allowed us to determine the thermodynamic equilibrium constant of Alizarin Red S (1,2-dihydroxyanthraquinone-3-sodium sulfonate) and to obtain the fluorescence spectra of chlorophyll and anthocyanins (two natural pigments). The multifunctional spectrophotometer allows one to perform real-time spectral analysis, offers an easy and fast calibration process as an alternative to the commonly applied calibration approach by the diffraction grid equation, and does not require the use of lenses for beam collimation since the webcam lens itself performs this function. The equipment was successfully applied in experiments conducted by a class of 30 students from high school in a science fair to aid them in learning chemistry.

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“…34 Silva et al developed a low-cost spectrometer by mounting a diffraction grating onto a webcam and then utilized this device to record absorbance and fluorescence spectra of various analytes in real time. 35 Other designs are also reported in the literature. [18][19][20][21][22][23][24][25][26]30,31 In this work, we constructed a custom single-beam fluorometer primarily of interlocking building bricks, optimized for NADH detection.…”

“…For example, Kvittingen and co-workers used LEDs as both a light source and detector (as described by Pokrzywnicka et al) to create a single-beam fluorescence spectrophotometer primarily out of interlocking building bricks. , Recently, Varra et al utilized interlocking building bricks, small optical components, and a smartphone camera to generate a fluorometer capable of monitoring single-particle fluorescence . Silva et al developed a low-cost spectrometer by mounting a diffraction grating onto a webcam and then utilized this device to record absorbance and fluorescence spectra of various analytes in real time . Other designs are also reported in the literature. − ,, …”

How Technologies Assisted Science Learning at Home During the COVID-19 Pandemic

“…Silva et al ( 2021 ) introduced a webcam-based spectrophotometer that can collect emission, absorption, and fluorescence spectra with a cost <20 USD but fully equipped with a diffraction grating and a slit to select wavelengths with ∼1 nm resolution in the range from 380 to 1000 nm. Simpler colorimetric analyses without the need of light circuits to select wavelength are possible, thanks to the separate nature of channels for red, green, and blue light in camera detectors.…”

Iron Quantification in Dietary Supplements using Four Colorimetric Assays

“…In 2020, Kovarik et al reviewed laboratory experiments carried out using digital images obtained using smartphones, desktop scanners, and webcams. Since then, several new laboratory experiments involving digital images have been published. − …”