Reversible light-controlled fluorescence switch of block polymer-grafted carbon dots and cellular imaging.

A novel type of aggregation-induced emission (AIE) nanoparticles, which are carbon dots (CDs) grafted with block polymer of tetraphenylethylene, spiropyran and -isopropylacrylamide (CD--poly((TPE--SPA)--NIPAM)), was synthesized. The CD--poly((TPE--SPA)--NIPAM) nanoparticles can emit weak cyan fluorescence in tetrahydrofuran, while showing AIE-enhanced cyan fluorescence in water and solid film. The fluorescence of the CD--poly((TPE--SPA)--NIPAM) nanoparticles can reversibly transform cyan to red with UV/visible light irradiation, and functioned as a reversible fluorescence photoswitch.

A novel method for aqueous synthesis of CdTe duantum dots.

We have developed a simple and an economical one-pot method to synthesize water-soluble CdTe quantum dots (QDs) using hydroxylamine hydrochloride (HAH) as reduction and l-cysteine (CYS) as the ligand. The size of the CdTe QDs could easily be controlled by the duration of reflux and monitored by absorption and photoluminescence spectra. The factors influencing the photoluminescence quantum yields (PL QYs) on the QYs of CdTe NCs were investigated and the optimum conditions were determined.

An ultrasensitive method for the determination of melamine using cadmium telluride quantum dots as fluorescence probes.

An ultrasensitive and simple method for the determination of melamine was developed based on the fluorescence quenching of thioglycolic acid (TGA) capped CdTe quantum dots (QDs) at pH 11.0. In strong alkaline aqueous solution, the selectivity of the method has been greatly improved due to most heavy metal ions show no interference as they are in the precipitation form or in their anion form.

Ultrasensitive determination of copper in complex biological media based on modulation of plasmonic properties of gold nanorods.

Accurate determination of copper in complex biological media such as cells is quite difficult, and an analytical strategy based on copper-modulated formation of core-shell gold nanorods is described. Selective and label-free sensing can be achieved by measuring the change in the localized surface plasmon resonance absorption. The technique can determine trace amounts of copper in human serum, urine, and red blood cells without or with minimal sample pretreatment.

Multiplex plasmonic sensor for detection of different metal ions based on a single type of gold nanorod.

In this paper, a label-free multiplex plasmonic sensor has been developed to selectively determine different metal ions including Fe(3+), Hg(2+), Cu(2+), and Ag(+) ions based on a single type of gold nanorod (GNR). Under proper conditions, these metal ions can react with GNRs, resulting in changes of nanostructure and composition. The determination of Fe(3+), Hg(2+), Cu(2+), and Ag(+) ions is therefore readily implemented due to changes of longitudinal plasmon wavelength (LPW) of nanorods.

Sensitive and simultaneous detection of different disease markers using multiplexed gold nanorods.

A multiplexed bioanalytical assay is produced by incorporating two types of gold nanorods (GNRs). Besides retaining the desirable features of common GNRs LSPR sensors, this sensor is easy to fabricate and requires only a visible-NIR spectrometer for detection. This assay can simultaneously detect different acceptor-ligand pairs by choosing the proper GNRs possessing various LPWs in a wide detection wavelength range and can be developed into a high-throughput detection method.