Colorimetric sensor arrays: Interplay of geometry, substrate and immobilization

Environmental contaminants pose a substantial health risk in many areas of the world. One of these risks is contamination of water with toxic organic species, such as herbicides and insecticides. Here we describe the discovery and properties of a set of fluorescent chemosensors that respond to micromolar concentrations of a broad range of common organic pesticides. The chemosensors are short DNA-like oligomers with fluorophores replacing DNA bases that are assembled via DNA synthesizer. We screened a library of 1296 tetrameric compounds on polystyrene microbeads, and identified a set of chemosensor sequences that respond strongly to a set of structurally varied pesticide analytes. We show that ten chemosensors on beads can be used to detect and identify 14 different common pesticides at 100 µM, using the pattern of fluorescence intensity and wavelength changes. Limits of detection for two analytes were as low as 2 µM. The chemosensors are shown to function successfully in a practical setting, correctly identifying unknown pesticide contaminants in water from Felt Lake, California. The results establish a simple, low cost strategy for sensing environmental spills of toxic organics.

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“…Future work will be aimed at increasing the sensitivity of this approach using flow-based concentration strategies. 23,31 …”

Section: Discussionmentioning

confidence: 99%

DNA as an environmental sensor: detection and identification of pesticide contaminants in water with fluorescent nucleobases

2017

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“…[4][5][6] The colorimetric analysis method is faster, but is more likely to destroy the sample. 7,8 In the eld of spectroscopic methods, our research group used laser-induced breakdown spectroscopy to measure the content of pesticide residues on the fruit surface.…”

Section: Introductionmentioning

confidence: 99%

Detection of pesticide residue distribution on fruit surfaces using surface-enhanced Raman spectroscopy imaging

Chen

Dong

2018

RSC Adv.

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Surface-enhanced Raman spectroscopy (SERS) is an emerging technique for the detection of pesticide residues on food surfaces, permitting quantitative measurement of pesticide residues without pretreating the sample. However, previous studies have mainly involved the single Raman spectrum of samples, while have given little information on pesticide residue distribution. In this paper, gold nanoparticles were used as surface enhancers to obtain the Raman spectra of omethoate and chlorpyrifos, using the Raman shifts of 413 cm À1 (omethoate) and 346 & 634 cm À1 (chlorpyrifos) as the peaks of interest.Different concentrations of pesticide solution were quantitatively analyzed and the regression curve model was established, whereby the solutions of omethoate and chlorpyrifos were used to study the distribution of pesticide residues on an apple surface by SERS microscopy imaging. Our study shows that this method can achieve rapid and quantitative detection and obtain basic information about the distribution of pesticide residues during pesticide application, which has the potential to be applied to the studies of the diffusion and absorption processes of pesticides in agricultural products.

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“…In MEMS sensors, this is generally either deflection or change in oscillating frequency of a polymer-coated microcantilever. Finally, optical sensors include those based on materials in which analyte vapor induces a change in the way light is absorbed, emitted, or refracted by the sensing material (22)(23)(24)(25)(26)(27)(28)(29)(30). These include sensors based on vapochromic dyes (24)(25)(26)(27), fluorescence (28,29), chemiluminescence (30,31), and surface plasmon resonance (32, 33).…”

Section: Sensor Typesmentioning

confidence: 99%

Sensor Array Design for Complex Sensing Tasks

Johnson

Rose-Pehrsson²

2015

Annual Rev. Anal. Chem.

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Chemical detection in complex environments presents numerous challenges for successful implementation. Arrays of sensors are often implemented for complex chemical sensing tasks, but systematic understanding of how individual sensor response characteristics contribute overall detection system performance remains elusive, with generalized strategies for design and optimization of these arrays rarely reported and even less commonly adopted by practitioners. This review focuses on the literature of nonspecific sensor array design and optimization strategies as well as related work that may inform future efforts in complex sensing with arrays.

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Colorimetric sensor arrays: Interplay of geometry, substrate and immobilization

Cited by 54 publications

References 31 publications

DNA as an environmental sensor: detection and identification of pesticide contaminants in water with fluorescent nucleobases

DNA as an environmental sensor: detection and identification of pesticide contaminants in water with fluorescent nucleobases

Detection of pesticide residue distribution on fruit surfaces using surface-enhanced Raman spectroscopy imaging

Sensor Array Design for Complex Sensing Tasks

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