声化学及其发展

本文通过对声化学发展历史的回顾及其作用原理的研究 ,旨在探讨声化学在化学反应方面的应用 。

Alcohol dehydrogenase coexisted solid-state electrochemiluminescence biosensor for detection of p53 gene

An alcohol dehydrogenase （ADH）-coexisted solidstate electrochemiluminescence （ECL） biosensor for sensitive detection of the p53 gene was developed. The electrode modified by multiwalled carbon nanotubes, Ru（bpy）]2＋3 and polypyrrole （ MWNTs-Ru （bpy） ]2＋3 -PPy ） was prepared to adsorb the ssDNA by electrostatic interactions. Then, the ssDNA recognized the gold nanoparticles （AuNPs）-labeled p53 gene and produced the AuNPs-dsDNA electrode with the AuNPs layer. The AuNPs layer adsorbed the ADH molecules for producing the ECL signal. Thus, the biosensor was based on coupling enzyme substrate reaction with solid-state ECL detection, and it displayed good sensitivity and specificity. The detection limit of the wild type p53 sequence （wtp53） is as low as 0. 1 pmol/L and the discrimination is up to 57. 1% between the wtp53 and the muted type p53 sequence （mtp53）. The amenability of this method to the analyses of p53 from normal and cancer cell lysates is demonstrated. The signal of wtp53 in the MGC-803 gastric cancer cell lysates turns out to be about 61.8% that of the wtp53 in the GES-1 normal gastric mucosal cell lysates, and the concentration of the wtp53 is found to decrease about 59 times. The method is highly complementary to enzyme-linked immunosorbent assay （ELISA）, and it holds promise for the diagnosis and management of cancer.

Radiation-Induced Graft Polymerization of Sodium 4-Styrene Sulfonate onto Multiwalled Carbon Nanotubes and Their Application as Electrogenerated Chemiluminescence Biosensors

Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was immobilized onto a sulfonated nanotube-supporting electrode with tris（2,2＇-bipyridyl） ruthenium（II） complex to form an electrogenerated chemilluminesce sensor of alcohol. When it was used to detect alcohol in cyclic voltammetric measurements, the sensor showed the linearity over the range of 1.0 × 10^-4 M-5.0 ×10^-2 M, with a correlation coefficient of 0.992 and a detection limit of 1.9 ×10^-6 M. In electrogenerated chemilluminesce detection, it showed linearity over 5.0 × 10^-4 M-1.0 × 10^-2 M, with a correlation coefficient of 0.986 and a detection limit of 1.0 × 10^-6 M. The sensor was demonstrated to be able to detect ethanol in commercial drinks.

上转换纳米粒子在食品分析中的应用研究进展

上转换纳米粒子由于其诸多优点已发展成为一类新兴的荧光生物探针和光学分析纳米材料。上转换纳米粒子因其具有毒性低、成本低、生物相容性好、化学稳定性好等优点,被广泛应用于各个领域。上转换纳米粒子具有独特的发光形式,它将低能辐射转化为高能辐射,和传统的染料和量子点等依靠下转换的发光材料相比,它可以通过近红外光激发,因此在生物医学及食品分析中有其不可比拟的优点。综述上转换纳米粒子的特性和制备方法,着重介绍近年来上转换纳米粒子在食品毒素、食源性致病菌、氨基酸、维生素和微量元素的快速高效检测中的研究进展,并对上转换发光纳米材料的应用前景进行分析和展望。

Facet-dependent electrochemiluminescence spectrum of nanostructured ZnO

A facet-dependent electrochemiluminescence (ECL) behavior was found for nanostructured ZnO with different dominant exposing planes.The ECL spectrum of nanostructured ZnO was recorded by the emission scan mode with a fluorescence spectrometer and applied to investigate the difference of surface state for different crystal planes.Electronic structure calculations based on density functional theory were used to study the effect of crystal plane on the band structure and density of states.It revealed that the ECL emission was originated primarily from the recombination of electrons from Zn 4s and the hole from O 2p,which could be utilized to study the physical and chemical properties of surface structures of as-prepared nanostructured ZnO.A physical model was suggested to elucidate the differences of ECL spectra.A concept was proposed that the energy released as photons during ECL process of nanocrystalline semiconductor materials will be correlated with the energy level of active sites located at different crystal planes.

Photoluminescence and surface photovoltage properties of Zn Se nanoribbons

ZnSe nanoribbons were synthesized with chemical vapor deposition route. The excitation power-dependent photol and surface photovoltage （SPV） techniques were used to study the optoelectronic properties of the as-grown ZnSe nanoribbons. Three deep defect （DD）-related emission bands, respectively, centered at 623 nm （DD1）, 563 nm （DD2） and 525 nm （DD3）, emerge orderly with increasing the excitation power, which is attributed to the saturation of the DD states from deeper to shallower level. The SPV spectrum and the corresponding phase spectrum show that DD1 mainly acts as recombination center, while DD2 and DD3 can act as both the recombination center and electron traps. The influence of the trapping electrons on the SPV response dynamic was studied with transient SPV.

Direct vapor phase growth process and robust photoluminescence properties of large area MoS2 layers

There has been growing research interest in the use of molybdenum disulfide in the fields of optoelectronics and energy harvesting devices, by virtue of its indirect-to-direct band gap tunability. However, obtaining large area thin films of MoS2 for future device applications still remains a challenge. In the present study, the amounts of the precursors （S and MOO3） were varied systematically in order to optimize the growth of highly crystalline and large area MoS2 layers by the chemical vapor deposition method. Careful control of the amounts of precursors was found to the key factor in the synthesis of large area highly crystalline flakes. The thickness of the layers was confirmed by Raman spectroscopy and atomic force microscopy. The optical properties and chemical composition were studied by photoluminescence （PL） and X-ray photoelectron spectroscopy. The emergence of strong direct excitonic emissions at 1.82 eV （A-exciton, with a normalized PL intensity of -55 × 10^3） and 1.98 eV （B-exciton, with a normalized PL intensity of -5 × 10^3） of the sample at room temperature clearly indicates the high luminescence quantum efficiency. The mobility of the films was found to be 0.09 cm^2/（V.s） at room temperature. This study provides a method for the controlled synthesis of high-quality two-dimensional （2D） transition metal dichalcogenide materials, useful for applications in nanodevices, optoelectronics and solar energv conversion.

Interaction between water molecules and 3C-SiC nanocrystal surface

The influence of water permeates almost all areas including biochemistry,chemistry,physics and is particularly evident in phenomena occurring at the interfaces of solid surface such as SiC nanocrystals,which are promising nanomaterials and exhibit unique surface chemical properties.In this paper,the quantum confinement effect and stability of 3C-SiC nanocrystals in aqueous solution as well as photoluminescence properties in water suspensions with different pH values are reviewed based on design and analysis of surface structures.On this basis,the significant progress of 3C-SiC nanocrystals in efficiently splitting water into usable hydrogen is summarized and the relative mechanisms are described.In addition,the water-soluble 3C-SiC quantum dots as robust and nontoxic biological probes and labels also are introduced as well as future prospects given.

Enhanced photoluminescence from porous silicon microcavities by rare earth doping

The photoluminescence(PL) properties of porous silicon microcavities(PSMs) in the visible range at room temperature are improved by doping the rare earth ytterbium(Yb) into PSMs prepared by the electrochemical etching method.It is observed that PSMs doped with the rare earth have an emission band around 630 nm.Compared with the single-layer porous silicon(PS) film,the PSMs doped with Yb have narrower and stronger PL spectrum.