ANALYST
·
2012
·Vol. 138
·期 4
·1219-1225
·
IF 4.23
Xindong Wang,Jing Dong,Huami Ming,Shiyun Ai
A novel strategy was proposed for preparing a highly sensitive glycoprotein sensor based on molecularly imprinted polymers (MIP), which was electropolymerized with o-phenylenediamine and 3-aminophenylboronic acid monohydrate in the presence of template molecules (bovine serum albumin (BSA)). Sensitivity improved dramatically owing to the application of a graphene–Au nanoparticles hybrid as the electrode modifier, and the immobilization of a large amount of 6-ferrocenylhexanethiol, as the electroactive species, onto nanoparticles. The quantification of BSA was realized by detecting the electrochemical oxidation signal of 6-ferrocenylhexanethiol, which was bonded onto the electrode. Under optimized conditions, a good relationship was obtained between the response current and logarithm of BSA concentration in the range of 1.0 × 10−11 to 1.0 × 10−5 g mL−1 with a detection limit of 7.5 × 10−12 g mL−1 (S/N = 3). The resulting MIP sensor displayed good selectivity, reproducibility and stability.
研究领域:
分析化学
·
生物传感器
·
纳米生物技术
·
分子识别
·
电化学传感
✓ 已验证
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Cheng Du,Chenglong Qiu,Zhongying Fang,Ping Li,Yijing Gao,Jianguo Wang,Wei Chen
Electrocatalytic nitrogen reduction reaction (NRR), which can produce ammonia from N 2 and H 2 O under ambient conditions, has emerged as a promising sustainable alternative to the Haber-Bosch (H-B) process. However, their unsatisfied conversion efficiency and selectivity severely restrict the real utilization of NRR, owing to the stubborn triple bond in the N 2 molecule and the competitive hydrogen evolution reaction (HER). Here, inspired from the local microenvironment of the nitrogenase, we report for the first time a facile and general strategy to boost the NRR selectivity and activity through the self-assembled monolayer (SAM) of hexanethiol (HEX) on a series of metal electrocatalysts (Cu, Au, Pt, Pd and Ni). Molecular dynamics (MD) simulations suggest that the HEX SAM provides a hydrophobic microenvironment to impede the diffusion and adsorption of water molecules and promote that of N 2 molecules, thus inhibiting HER and simultaneously improving the NRR performance. Notably, among all the prepared samples, the highest Faradic efficiency (FE) of 50.5% is achieved on Cu-HEX with NH 3 formation rate (R) of 1.2 μg h −1 cm −2 . Remarkably, for the HER-favored Pt catalyst, the highest R of 26.4 μg h −1 cm −2 is also achieved on Pt-HEX with FE of 1.8% under 1 cm 2 of electrode area. The present strategy not only represents a general diffusion-controlled method to engineer high-performance NRR electrocatalysts, but also provides a new insight into the effect of surface chemistry of catalysts on the NRR process and kinetics.
研究领域:
电化学
·
催化
·
材料科学
·
化学工程
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Xiaomei Qin,Shihao Yang,Yapei Chen,Xiaoyun Qin,Jianbo Zhao,Wenjun Fang,Dan Luo
Palladium nanoparticles, which were prepared by modified hyperbranched polyglycerol (mHPG) as stabilizers, can be dispersed well in nonpolar organic solvents and form highly stable nanofluids. The influences of three mHPG products modified with cyclohexanethiol (CSHPG), dodecanethiol (DSHPG), and octadecanethiol (OSHPG) on the preparation and stability of the palladium nanoparticles were investigated. The stability and thermal conductivity enhancement of the hydrocarbon-based nanofluids with Pd@mHPG (Pd@CSHPG, Pd@DSHPG, and Pd@OSHPG) compared to the corresponding base fluid were investigated at different temperatures. The average diameters of nanoparticles stabilized by CSHPG, DSHPG, and OSHPG are within 2.7–3.6 nm. The palladium nanoparticles could be dispersed well in the nonpolar base fluid such as decalin. The nanofluids with Pd@DSHPG and Pd@OSHPG could remain stable for up to 330 days at room temperature. The nanofluid with Pd@DSHPG or Pd@OSHPG could be stable for more than 24 h at 110 °C. The thermal conductivity of the nanofluids improved with increasing temperature and the mass fraction of nanoparticles compared to the corresponding base fluid. The long alkyl chain-modified HPG can give better protection for nanoparticles from agglomeration and assist metal nanoparticles in enhancing the thermal conductivity of nanofluids.
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2017
·
IF 7.78
Li Zhang,Xiaofen Xiao,Yuzhi Xu,Danping Chen,Jun Chen,Yingjun Ma,Zong Dai,Xiaoyong Zou
A simple electrochemical strategy is reported for continuous monitoring of dynamic DNA methylation process over time. An electrochemical sensor was prepared by co-assembling of DNA probe and 6-mercapto-1-hexanol onto a gold electrode. The top of the DNA probe was labeled with 6-ferrocenylhexanethiol modified gold nanoparticle . The charge density between the C•G base pair was verified to be slightly reduced by DNA methylation, and could be further decelerated by ~ 25% upon co-locating a Br group onto methylated cytosine (mC). Therefore, in the presence of NaIO 4 /LiBr, the progressively methylated DNA on the sensor showed a clearly decreasing current over methylation time. The dynamic DNA methylation process was indicated continuously from the current decrease ratio, with a limit of detection of 0.0372 µM. The strategy is convenient, cost-effective, and enable continuous profiling methylation process without distortion. Besides, the strategy was successfully applied for the studies on inhibitor screening and flanking sequence preference of DNA methyltransferase 3a. The results show that the activity of DNA methyltransferase 3a can be mildly inhibited by epigallocatechin gallate , and varies towards different flanking sequence with an order of 5′-CCGG-3′ < 5′-CGCG-3′ < 5′-CGCA-3′.
研究领域:
电化学
·
分子生物学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）