Sustainable and green sensors based on polydimethyl siloxane (PDMS) or cellulose polymers, as a case of study of the use of portable instrumentation joined to a smartphone, have been tested. A smartphone camera was used to obtain images and was also coupled to a minispectrometer, without and with an optical fiber probe to register spectra. To study light influence on the analytical signal, light-emitting diode (LED), halogen light and daylight have been assayed. A corrective palette of 24 colors and a set with 45 colors from different color ranges were used as the validation set. The results indicated that halogen light was the best option to obtain the spectra. However, for digital image analysis, it was the LED light that gave a greater approximation of the RGB values of the real colors. Based on these results, the spectra and the RGB components of PDMS solid sensors doped with 1,2-naphtoquinone-4-sulfonate (NQS) for the determination of ammonium in water or urea in urine, PDMS doped with Griess reagent for developing the assay of nitrite in waters and cellulose sensors for the determination of hydrogen sulfide in the atmospheres have been obtained. The results achieved were good in terms of sensitivity and linearity and were comparable to those obtained using a laboratory benchtop instrument. Several rules for selecting the most suitable light source to obtain the spectra and/or images have been established and an image correction method has been introduced.
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http://dx.doi.org/10.3390/polym14204285 | DOI Listing |
Mikrochim Acta
January 2025
Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala, 678557, India.
Compared with previous decades, healthcare has emerged as a key global concern in light of the recurrent outbreak of pandemics. The initial stage in the provision of healthcare involves the process of diagnosis. Countries worldwide advocate for healthcare research due to its efficacy and capacity to assist diverse populations.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO, Brazil; Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, 13084-971, SP, Brazil. Electronic address:
Background: Distinct classes of environmental contaminants - such as microplastics, volatile organic compounds, inorganic gases, hormones, pesticides/herbicides, and heavy metals - have been continuously released into the environment from different sources. Anthropogenic activities with unprecedented consequences have impacted soil, surface waters, and the atmosphere. In this scenario, developing sensing materials and analytical platforms for monitoring water and air quality is essential to supporting worldwide environmental control agencies.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Computer Science, Faculty of Sciences and Humanities Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia.
Impedance-based biosensing has emerged as a critical technology for high-sensitivity biomolecular detection, yet traditional approaches often rely on bulky, costly impedance analyzers, limiting their portability and usability in point-of-care applications. Addressing these limitations, this paper proposes an advanced biosensing system integrating a Silicon Nanowire Field-Effect Transistor (SiNW-FET) biosensor with a high-gain amplification circuit and a 1D Convolutional Neural Network (CNN) implemented on FPGA hardware. This attempt combines SiNW-FET biosensing technology with FPGA-implemented deep learning noise reduction, creating a compact system capable of real-time viral detection with minimal computational latency.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
School of Medical Technology, Xuzhou Medical University, Xuzhou, 221004, China. Electronic address:
Background: The early detection of Hepatocellular Carcinoma (HCC) is crucial for improving patient survival rates.Early diagnosis of HCC can significantly enhance treatment outcomes and reduce disease progression. Antigen detection of tumor markers is one of the important diagnostic methods for HCC.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, Shandong, 266237, China. Electronic address:
Background: The COVID-19 pandemic has significantly affected global health, economies, and societies, and highlighted the urgent need for rapid, sensitive, affordable, and portable diagnostic devices for respiratory diseases, especially in areas with limited resources. In recent years, there has been rapid development in integrated equipments using microfluidic chips and biochemical detection technologies. However, these devices are expensive and complex to operate, showing limited feasibility for in point of care tests (PoCTs).
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