A fluorescence biosensor for organophosphorus pesticide detection with a portable fluorescence device-based smartphone.

An innovative fluorescence biosensor was successfully developed to detect organophosphorus pesticide (OPs) by utilizing smartphone technology. The assay relied on the enzymatic activity of alkaline phosphatase (ALP), which facilitated the conversion of L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AAP) into L-ascorbic acid (AA). The AA that generated was then reactedwith o-phenylenediamine (OPD) to yield a fluorescent marker identified as 3-(1,2-dihydroxyethyl)furo[3,4-b]quinoxalin-1(3H)-one (DFQ).

A hybrid catalyst-triggered cascade reaction for cholesterol detection using a smartphone-based miniature fluorescent apparatus.

A new hybrid biological-chemical catalyst, magnetic nanoparticles functionalized with cholesterol oxidase (FeO/APTES/ChOx), was developed for cholesterol detection. In the presence of cholesterol, the enzyme produced HO, which facilitated the generation of fluorescent molecules from the fluorogenic substrate with the assistance of FeO nanoparticles. A smartphone camera with a miniature fluorescent apparatus was used to assess fluorescence emission.

A portable fluorescence detection device based on a smartphone employing carbon nanodots for Mn sensing.

The measurement of fluorescence emission for quantitative analysis is typically based on a traditional spectrofluorometer, which limits an onsite detection approach. Thus, an alternative device should be developed for fulfilling this analysis outside of the laboratory. Therefore, a low-cost, portable, and low-energy consumption fluorescence reader-based smartphone device was developed.

Simultaneous preconcentration and fluorescence detection of ATP by a hybrid nanocomposite of magnetic nanoparticles incorporated in mixed metal hydroxide.

A new approach for increasing the sensitivity of adenosine triphosphate (ATP) detection was demonstrated. The assay was based on the synergetic function of a hybrid nanocomposite (MNPs@MMH) composed of magnetic nanoparticles (MNPs) incorporated in a mixed metal hydroxide (MMH). MNPs@MMH can be utilized as an efficient green extractant and peroxidase catalyst.

A simple strategy to enhance the sensitivity of fluorescent sensor-based CdS quantum dots by using a surfactant for Hg detection.

A simple strategy to enhance the detection sensitivity of fluorescent sensor-based CdS quantum dots (CdS QDs) for the detection of mercury ions (Hg) was demonstrated. L-Cysteine-capped CdS QDs (L-Cyst-CdS QDs) were synthesized and utilized as a probe for selective detection of Hg. The fluorescence intensity of the L-Cyst-CdS QDs was quenched in the presence of Hg.

Highly selective circular dichroism sensor based on d-penicillamine/cysteamine‑cadmium sulfide quantum dots for copper (II) ion detection.

A highly selective circular dichroism sensor based on cysteamine-capped cadmium sulfide quantum dots (Cys-CdS QDs) was successfully developed for the determination of Cu. Basically, the Cys-CdS QDs are not active in circular dichroism spectroscopy. However, the circular dichroism probe (DPA@Cys-CdS QDs) can be simply generated in situ by mixing achiral Cys-CdS QDs with D-penicillamine.

Fluorescence chemodosimeter for dopamine based on the inner filter effect of the in situ generation of silver nanoparticles and fluorescent dye.

A new strategy for the sensitive and selective detection of dopamine (DA) was proposed. The chemodosimeter design was based on the measurement of the fluorescent quenching of fluorescein dye caused by the in situ generation of silver nanoparticles (AgNPs). The AgNPs can be simply generated by a reaction between DA and Ag in the presence of polymethacrylic acid (PMAA).

Circular dichroism sensor based on cadmium sulfide quantum dots for chiral identification and detection of penicillamine.

A new chemical sensor based on the measuring of circular dichroism signal (CD) was fabricated from cysteamine capped cadmium sulfide quantum dots (Cys-CdS QDs). The chiral-thiol molecules, d-penicillamine (DPA) and l-penicillamine (LPA), were used to evaluate potentials of this sensor. Basically, DPA and LPA provide very low CD signals.

Cysteamine CdS quantum dots decorated with Fe3+ as a fluorescence sensor for the detection of PPi.

A new sensitive and selective fluorescence sensor for the detection of pyrophosphate (PPi) in aqueous media based on the Fe(3+) decorated cysteamine CdS QDs ([Cys-CdS QDs]-Fe(3+)) was proposed. The presence of PPi can induce the fluorescence quenching of [Cys-CdS QDs]-Fe(3+) due to the high formation constants between the phosphate group and Fe(3+). Because the complex between Fe(3+) and PPi acts as an efficient quencher, the concentration of PPi can be evaluated by tracking the degree of fluorescence quenching.