Multiplex immunochromatographic test strip based on multicolor gold nanoparticles for the simultaneous detection of neomycin, penicillin, and chloramphenicol in food samples.

In this study, we demonstrated an approach for the development of multiplex immunochromatographic test strip (MICS) for neomycin (NEO), penicillin (PEN), and chloramphenicol (CAP) detection using three different-colored gold nanoparticles. The gold nanoparticles: gold nanospheres (red), gold nanostars (blue), and gold nanoflowers (black) were applied as labels for MICS fabrication. The proposed MICS achieved a clearly visible limit of detection with cut-off values of 500, 5, and 0.

Gamma Irradiation and Exogenous Proline Enhanced the Growth, 2AP Content, and Inhibitory Effects of Selected Bioactive Compounds against α-Glucosidase and α-Amylase in Thai Rice.

Exogenous proline can improve the growth, aroma intensities, and bioactive compounds of rice. This study evaluated the effects of gamma irradiation under proline conditions on the 2-acetyl-1-pyrroline (2AP), phenolic, and flavonoid contents of rice. Moreover, the bioactive compounds of gamma-irradiated rice under proline conditions that inhibited α-glucosidase and α-amylase were evaluated by in silico study.

Dual-color immunochromatographic test strip for simultaneous sensitive detection of malachite green and leucomalachite green residues in fish and shrimp meat samples.

A sensitive dual immunochromatographic test strip (dual-ICTS) was developed to detect malachite green (MG) and its metabolite, leucomalachite green (LMG), using two types of gold nanoparticles: round-shaped (red) and star-shaped (blue). The detection limits were determined to be 0.221 μg L for MG and 0.

A nanosilica-coated thread-based analytical device for nitrate and nitrite detection in food samples.

A new microfluidic thread-based analytical device (μTAD) for nitrate and nitrite determination in food samples was developed. The cotton thread substrate was coated with nanosilica to increase its hydrophilicity and stability, and polylactic acid was applied to one end of the nanosilica-coated thread to constrain the fluid flow along the thread in one direction. Quantification of nitrate and nitrite was based on the modified Griess reaction, using sulfanilamide and N-(1-naphthyl) ethylenediamine as chromogenic reagents, and utilizing a distance-based detection technique.

Smartphone-based imaging colorimetric assay for monitoring the quality of curcumin in turmeric powder.

This research developed a colorimetric assay for semi-quantitative curcumin detection. The screening test was performed using a ferric chloride to form a brownish color which was further used to evaluate the amount of curcumin in the turmeric powder samples. The quantitative assay was performed based on the color intensity of the curcumin target using a smartphone digital image colorimetry with a developed lightbox constructed with a white light-emitting diodes (LED) light source as the measurement device.

Rapid colorimetric assay based on the oxidation of 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid-diammonium salt for nitrite detection in meat products.

This work developed a rapid colorimetric method for nitrite detection in meat products. The detection was based on the reaction of nitrite with 60 mM HCl to produce radicals which further oxidized ABTS (50 µM) to form a water-soluble blue-green product (ABTS). The absorbance was measured at a maximum absorption wavelength of 412.

A highly sensitive hyperbranched Au plasmonic blackbody immunochromatographic assay for detection of leucomalachite green in fish and shrimp.

A novel immunochromatographic assay (ICA) based on hyperbranched Au plasmonic blackbodies (AuPBs) with a smartphone readout was fabricated for the detection of leucomalachite green (LMG) in fish and shrimp products. The ICA was carried out in a competitive immunoassay format with AuPBs as labels. The developed AuPBs-ICA allowed for the LMG detection with a low detection limit (0.

Nanozymes paper-based analytical device for the detection of organophosphate pesticides in fruits and vegetables.

In this work, copper oxide nanoparticles (CuONPs) nanozymes paper-based analytical device was designed for the rapid detection of organophosphate pesticides in fruits and vegetables. The paper-based analytical device was modified with silica oxide nanoparticles to enhance the assay sensitivity. CuO nanozymes displayed peroxidase-like activity and catalyzed the oxidation of o-dianisidine in the presence of HO from the hydrolysis of acetylthiocholine.

Silica nanoparticle-modified paper strip-based new rhodamine B chemosensor for highly selective detection of copper ions in drinking water.

A new rhodamine B derivative (RDB) was synthesized and utilized for the colorimetric detection of copper ions (Cu). This chemosensor utilized a paper strip as a support and a smartphone as a detector for on-site quantitative detection of Cu in water samples. Silica nanoparticles (SiNPs) were investigated as the modifier nanoparticles to achieve uniform color on the paper strip and showed a color response 1.

Fabrication and characterization of polycaprolactone/cellulose acetate blended nanofiber mats containing sericin and fibroin for biomedical application.

Polycaprolactone/cellulose acetate blended nanofiber mats containing sericin and fibroin were fabricated by electrospinning process to study the effect of sericin and fibroin on the physical and structural properties, wettability, degradability, elastic modulus, cell adhesion, and cell cytotoxicity of the electrospun nanofibers. Polycaprolactone/cellulose acetate solution was prepared with different percentage ratio of sericin and fibroin to be the running solution. Nanofibers were spun at fixed solution flow rate, flying distance, and operating voltage.

A portable device as a paper test strip platform with smartphone application for detection of branched-chain amino acids in edible insects.

A novel strategy is presented for simple, sensitive and selective branched-chain amino acids (BCAAs) detection in edible insects on a paper test strip device readout with a smartphone. Silver nanoparticles (AgNPs) were applied, interacting with dye, which provided 1.5 times higher color intensity than the one without AgNPs.

Effect of gamma irradiation on growth, proline content, bioactive compound changes, and biological activity of 5 popular Thai rice cultivars.

Gamma irradiation is the technique used to induce plant mutation and it has affected both the physiological and biochemical compounds of the plant. Some new rice lines are also created through the gamma-irradiation technique. We investigated the effect of gamma irradiation on plant growth, volatile compounds, and the biological activity of gamma-irradiated rice extract compared to non-gamma-irradiated rice extract.

Ready-to-use, functionalized paper test strip used with a smartphone for the simultaneous on-site detection of free chlorine, hydrogen sulfide and formaldehyde in wastewater.

The simultaneous detection of free chlorine, hydrogen sulfide and formaldehyde in wastewater samples was performed. In this report, we designed and fabricated functionalized paper test strips featuring detection zones that use 3-aminopropyltriethoxysilane (APTES) for the immobilization of chromogenic substrates to detect free chlorine, hydrogen sulfide and formaldehyde. After multiple chromogenic reactions, red, blue and purple colors were obtained on the detection zones and analyzed using a smartphone.

Development of qualitative and quantitative immunochromatographic strip test assay for rapid and simple detection of leucomalachite green residual in aquatic animals.

A rapid and simple immunochromatographic strip test assay based on competitive format was developed for leucomalachite green (LMG) detection. LMG-bovine serum albumin and rabbit anti-sheep IgG were immobilized on nitrocellulose membrane for the test line and control line, respectively. Anti-LMG-colloidal gold conjugate was immobilized onto the conjugate pad.

On-site detection of heavy metals in wastewater using a single paper strip integrated with a smartphone.

A field paper-based heavy metal strip was designed and implemented for simultaneous detection of the heavy metals Zn, Cr, Cu, Pb and Mn in wastewater samples. The colorimetric paper strip was fabricated by drop-casting of chromogenic reagents onto detection zones. When the fabricated paper strip was exposed to Zn, Cr, Cu, Pb and Mn, multiple colors appeared that were then recorded with a smartphone followed by processing in the Color Picker application.

Development of the simultaneous colorimetric enzymatic detection of sucrose, fructose and glucose using a microfluidic paper-based analytical device.

Herein, we propose the first fabrication of a microfluidic paper-based analytical device (μPAD) as a simple, rapid and selective method for the simultaneous detection of sucrose, fructose and glucose for quality monitoring in the sugar industry. Multiplex detection of the three analytes was achieved by three detection zones designed on a single device. Each detection zone on the μPAD was modified with enzymes, chromogenic reagents and specific substrates.

Electrospun Chitosan-Gelatin Biopolymer Composite Nanofibers for Horseradish Peroxidase Immobilization in a Hydrogen Peroxide Biosensor.

A biosensor based on chitosan-gelatin composite biopolymers nanofibers is found to be effective for the immobilization of horseradish peroxidase to detect hydrogen peroxide. The biopolymer nanofibers were fabricated by an electrospining technique. Upon optimization of synthesis parameters, biopolymers nanofibers, an average of 80 nm in diameter, were obtained and were then modified on the working electrode surface.

Unmodified gold nanoparticles as a simple colorimetric probe for ramoplanin detection.

In this paper unmodified gold nanoparticles (AuNPs) were used as a sensing element to detect ramoplamin. Detection relies on the fact that the dispersed AuNPs solution is red due to the intense surface plasmon absorption band at 530 nm whereas the AuNPs solution in the presence of ramoplanin is blue. Upon aggregation, there is a significant change in absorbance intensity at 620 nm.