Jing-Ya Zhao

Near-Infrared Electrogenerated Chemiluminescence of Ultrasmall Ag2Se Quantum Dots for the Detection of Dopamine

The near-infrared (NIR) electrogenerated chemiluminescence (ECL) of water-dispersed Ag(2)Se quantum dots (QDs) with ultrasmall size was presented for the first time. The Ag(2)Se QDs have shown a strong and efficient cathodic ECL signal with K(2)S(2)O(8) as coreactant on the glassy carbon electrode (GCE) in aqueous solution. The ECL spectrum exhibited a peak at 695 nm, consistent with the peak in photoluminescence (PL) spectrum of the Ag(2)Se QDs solution, indicating that the Ag(2)Se QDs had no deep surface traps. Dopamine was chosen as a model analyte to study the potential of Ag(2)Se QDs in the ECL analytical application. The ECL signal of Ag(2)Se QDs can also be used for the detection of the dopamine concentration in the practical drug (dopamine hydrochloride injection) containing several adjuvants such as edetate disodium, sodium bisulfite, sodium chloride and so on. The Ag(2)Se QDs could be a promising candidate emitter of ECL biosensors in the future due to their fantastic features, such as ultrasmall size, low toxicity, good water solubility, and near infrared (NIR) fluorescent emission.

Enzyme-induced metallization as a signal amplification strategy for highly sensitive colorimetric detection of avian influenza virus particles.

A novel colorimetric assay method based on enzyme-induced metallization has been proposed for detection of alkaline phosphatase (ALP), and it was further applied to highly sensitive detection of avian influenza virus particles coupled with immunomagnetic separation. The enzyme-induced metallization-based color change strategy combined the amplification of the enzymatic reaction with the unique optical properties of metal nanoparticles (NPs), which could lead to a great enhancement in optical signal. The detection limit for ALP detection was 0.6 amol/50 μL which was 4-6 orders of magnitude more sensitive than other metal NP-based colorimetric methods. Moreover, this technique was successfully employed to a colorimetric viral immunosensor, which could be applied to complex samples without complicated sample pretreatment and sophisticated instruments, and a detection limit as low as 17.5 pg mL(-1) was achieved. This work not only provides a simple and sensitive sensing approach for ALP and virus detection but also offers an effective signal enhancement strategy for development of a highly sensitive nonaggregation metal NP-based colorimetric assay method.

Ultrasmall Magnetically Engineered Ag2Se Quantum Dots for Instant Efficient Labeling and Whole-Body High-Resolution Multimodal Real-Time Tracking of Cell-Derived Microvesicles.

Cell-derived microvesicles (MVs) are natural carriers that can transport biological molecules between cells, which are expected to be promising delivery vehicles for therapeutic purposes. Strategies to label MVs are very important for investigation and application of MVs. Herein, ultrasmall Mn-magnetofunctionalized Ag2Se quantum dots (Ag2Se@Mn QDs) integrated with excellent near-infrared (NIR) fluorescence and magnetic resonance (MR) imaging capabilities have been developed for instant efficient labeling of MVs for their in vivo high-resolution dual-mode tracking. The Ag2Se@Mn QDs were fabricated by controlling the reaction of Mn(2+) with the Ag2Se nanocrystals having been pretreated in 80 °C NaOH solution, with an ultrasmall size of ca. 1.8 nm, water dispersibility, high NIR fluorescence quantum yield of 13.2%, and high longitudinal relaxivity of 12.87 mM(-1) s(-1) (almost four times that of the commercial contrast agent Gd-DTPA). The ultrasmall size of the Ag2Se@Mn QDs enables them to be directly and efficiently loaded into MVs by electroporation, instantly and reliably conferring both NIR fluorescence and MR traceability on MVs. Our method for labeling MVs of different origins is universal and free of unfavorable influence on intrinsic behaviors of MVs. The complementary imaging capabilities of the Ag2Se@Mn QDs have made the long-term noninvasive whole-body high-resolution dual-mode tracking of MVs in vivo realized, by which the dynamic biodistribution of MVs has been revealed in a real-time and in situ quantitative manner. This work not only opens a new window for labeling with QDs, but also facilitates greatly the investigation and application of MVs.

Synthesis of sub-5 nm Au–Ag alloy nanoparticles using bio-reducing agent in aqueous solution

Bio-reducing agent NADPH with relatively weak reducibility and favourable structure simultaneously reduced Au and Ag ions into sub-5 nm alloy nanoparticles in aqueous solution at room temperature.

Fluorescence-Converging Carbon Nanodots-Hybridized Silica Nanosphere.

Ultrabright carbon nanodots-hybridized silica nanospheres (CSNs) are synthesized through the Stöber process of silane functionalized C-dots. The fluorescence of carbon nanodots is converged intensely. A CSN is about 3800 times brighter than a single-carbon nanodot. Along with their high brightness and low cytotoxicity, CSNs also indicate their potential application in cellular labeling.

Infiltration of M2‐polarized macrophages in infected lymphatic malformations: possible role in disease progression

Lymphatic malformations (LMs), slow‐flow vascular anomalies resulting from abnormal development of lymphatic channels, often progress rapidly after trauma or infection.