Simpler Procedure and Improved Performance for Pathogenic Bacteria Analysis with a Paper-Based Ratiometric Fluorescent Sensor Array

Abstract

Bacterial infections are the leading cause of morbidity and mortality in the world, particularly due to a delay in treatment and misidentification of the bacterial species causing the infection. Therefore, rapid and accurate identification of these pathogens has been of prime importance. The conventional diagnostic techniques include microbiological, biochemical, and genetic analyses, which are time-consuming, require large sample volumes, expensive equipment, reagents, and trained personnel. In response, we have now developed a paper-based ratiometric fluorescent sensor array. Environment-sensitive fluorescent dyes (3-hydroxyflavone derivatives) pre-adsorbed on paper microzone plates fabricated using photolithography, upon interaction with bacterial cell envelopes, generate unique fluorescence response patterns. The stability and reproducibility of the sensor array response were thoroughly investigated, and the analysis procedure was refined for optimal performance. Using neural networks for response pattern analysis, the sensor was able to identify 16 bacterial species and recognize their Gram status with an accuracy rate greater than 90%. The paper-based sensor was stable for up to 6 months after fabrication and required 30 times lower dye and sample volumes as compared to the analogous solution-based sensor. Therefore, this approach opens avenues to a state-of-the-art diagnostic tool that can be potentially translated into clinical applications in low-resource environments.

Back to the Drawing Board: A Unifying First-Principle Model for Correlating Sample UV–Vis Absorption and Fluorescence Emission

“…UV–vis absorption and fluorescence spectroscopies are the two most used methods in chemistry, biology, and materials sciences. − Understanding the relationship between the fluorophore light absorption and fluorescence emission is important not only for a fundamental understanding of materials photophysical properties but also for reliable fluorescence analysis. While the origins of light absorption and fluorescence emission have become common knowledge for most fluorescent materials, the interplay among the sample light absorption and emission can be highly complicated in many practical fluorescence applications. − Mechanistically, fluorophore light absorption must precede its fluorescence emission.…”

Rapid and sensitive naked eye detection of faecal pigments using their enhanced solid-state green fluorescence on a zinc acetate substrate

“…A fast and highly selective cellulose paper-based sensor is commonly used for the detection of various contaminants. [29][30][31] However, currently there is no rapid paper strip based screening test available for FPs detection. A comparison between the suggested method and previous methods for the detection of FPs is shown in Table S2.…”

A Paper-Based Fluorescent Sensor for Rapid Early Screening of Oral Squamous Cell Carcinoma

“…In recent years, a variety of newly developed sensors play an important role in the detection of biomarkers due to their small size and intelligence. − However, their high cost and requirement on equipment are often unacceptable to ordinary people. Due to the low cost, high adjustability, and low production difficulty, paper-based sensors have gradually been used as a new detection method in various scenarios, especially in developing countries that lack sufficient financial support. − Moreover, paper-based analytical devices with fluid flow channels can even quantitatively detect multiple substances simultaneously. − However, compared to the commercial sensors, the paper-based sensors cannot have special competitiveness in detection accuracy, which makes it difficult to exert their detection capabilities in the detection of a complex system with low target substrate concentration (such as saliva).…”