ANALYTICAL CHEMISTRY
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2017
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IF 6.32
Xiang-Ru Bai,Yi Zeng,Xiao-Dong Zhou,Xiao-Hua Wang,Ai-Guo Shen,Ji-Ming Hu
Field, reliable, and ultrasensitive detection of dipicolinic acid (DPA), a general biomarker of bacterial spores and especially Bacillus anthracis, is highly desirable but still challenging in current biometric security emergency response system. Herein we report an environmentally safe mercury(II) ions-mediated and competitive coordination interaction based approach for rationally designed surface-enhanced Raman scattering (SERS)-active gold nanoparticles (AuNPs), enabling rapid, ultrasensitive and zero-background detection of DPA without the pretreatment of samples. By means of competitiveness, these papain-capped gold nanoparticles (P-AuNPs) are induced to undergo controllable aggregation upon the addition of Hg2+ ions and DPA with a concentration range (1 nM∼8 μM), which correspondingly cause quantitative changes of SERS intensity of cresyl violet acetate (CVa) conjugated AuNPs. The decreased Raman intensity obtained by subtracting two cases of additives that contain only Hg2+ and the mixture of Hg2+ and DPA is proportional to the concentration of DPA over a range of 1 nM∼8 μM (R2 = 0.9824), with by far the lowest limit of detection (LOD) of 67.25 pM (0.01 ppb, S/N = 3:1). Of particular significance, mercury(II) ions actually play two roles in the process of measurements: a mediator for two designed competitive ligands (DPA and papain), and also a scavenger for the possibly blended ligands due to the different interaction time between DPA and the interferent with Hg2+ ions, which guarantees the interference-free detection of DPA even under real conditions.
研究领域:
分析化学
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生物医学
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环境科学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
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2019
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IF 5.256
Kang Zou,Yamin Fu,Ruiying Yang,Xiaohua Zhang,Cuicui Du,Jinhua Chen
By direct calcination of Cu 2+ -doped ZIF-8 in oxygen atmosphere, a new photoelectric material, CuO–ZnO heterojunction , was prepared. The morphology and structure were investigated in detail by several methods, such as scanning electron microscopy, transmission electron microscopy , nitrogen adsorption-desorption method and X-ray diffraction. Under visible light irradiation , CuO–ZnO heterojunction exhibits excellent PEC behavior in aqueous media with the presence of ascorbic acid (AA) and dissolved oxygen at −0.3 V. Taking the CA125-antibody functionalized CuO–ZnO heterojunction (CuO–ZnO-Ab 2 ) as a signal source, a novel photoelectrochemical (PEC) immunosensing platform was developed for ultrasensitive assay of CA125. Because of the target-induced introduction of photoelectric material to the sensing platform, the proposed PEC immunosensor has excellent performance for CA125 assay: near-zero background noise, wide linear response range (1 × 10 −5 U/mL to 100 U/mL) and low detection limit (3.16 × 10 −6 U/mL). The developed CuO–ZnO heterojunction and the related PEC sensing platform may have promising applications in ultrasensitive and highly accurate monitoring of various proteins in bioanalysis and disease diagnosis.
研究领域:
生物分析
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医学诊断
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材料科学
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
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IF 7.46
Yunwei Zhao,Ying Wang,Ruimei Yang,Hui Zhang,Yanfang Zhao,Xiangmin Miao,Lihua Lu
A zero-background fluorescent aptasensor for the ultrasensitive detection of pesticides has been successfully constructed, using poly(T) stabilized copper nanoparticles (CuNPs) as a fluorescent signal and three-dimensional (3-D) DNA walker as a signal amplifier. To fabricate the aptasensor, one strand of dsDNA and one strand of ssDNA are immobilized onto magnetic Fe 2 O 3 beads. The dsDNA is hybridized by the target aptamer contained DNA (Apt-1) and the partial complementary DNA which named as WS since it acts as a walking strand (WS) in DNA walker. Upon the specific binding between omethoate with Apt-1, WS becomes a free walking ssDNA strand. With the aid of nicking endonuclease, the 3-D DNA walker can produce a great quantity of poly(T) DNA during the WS walking. When the supernatant is added into ascorbic acid (AA) and Cu 2+ , poly(T) templated CuNPs forms and strong fluorescence generates. The developed aptasensor has a zero-background, and can ultrasensitively detect omethoate in the linear range of 0–200 nM with the detection limit of 0.22 nM. This zero-background aptasensor provides a facile strategy for pesticides determination in the fields of food safety and environmental monitoring.
研究领域:
分析化学
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生物技术
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环境科学
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DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2021
·Vol. 413
·期 25
·6279-6288
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IF 4.157
Zeng Zhiyao,Tang Juan,Zhang Ming,Pu Shouzhi,Tang Dianping
Herein, a novel signal-on photoelectrochemical (PEC) biosensor with nearly zero background noise (ZBN) was first fabricated to determine the presence of organophosphorus pesticide based on in situ formation of DNA-templated Ag 2 S photoactive materials, accompanied by hybridization chain reaction (HCR) signal amplification. The capture probe (S1) on the gold nanoparticle-modified electrode can hybridize with the aptamer molecule to generate a simple PEC biosensor. In the presence of a target molecule, the aptamer molecule is released on the double-stranded DNA (dsDNA)-modified PEC biosensor. Meanwhile, the capture probe remains on the electrode and can open the DNA hairpins (H1, H2) which are rich in cytosine, to trigger the HCR reaction. The rich “C” strands are uncovered after formation of a long dsDNA polymer strand, which can assemble multiple silver ions (Ag + ) by means of by C–Ag + –C chelation. Then, a large number of Ag 2 S can be generated by challenging with S 2− solution, producing a satisfactory photocurrent signal. The photoactive material is formed in situ, which eliminates the laborious operation. Moreover, the signal can be highly amplified with nearly zero background noise and HCR signal amplification. Under optimal conditions, the ZBN aptasensor exhibited high sensitivity and selectivity, with a low detection limit of 2 pg mL −1 for malathion. Importantly, the sensing platform can also be applied to determine the presence of malathion in real samples. Graphical abstract
In this assay, a novel signal-on photoelectrochemical biosensor with nearly zero background noise was first fabricated to determine the presence of organophosphorus pesticide based on in situ formation of DNA-templated Ag 2 S photoactive materials, accompanied by hybridization chain reaction signal amplification.
研究领域:
分析化学
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环境科学
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生物传感器
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农药检测
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PubMed
高影响因子
TALANTA
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2016
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IF 4.035
Liangfei Ouyang,Qian Liu,Chaoping Xu,Changgui Liu,Heng Liang
We developed paper-based powder X-ray diffraction (PP-XRD) to implement phase identification and/or crystal structure determination on paper-based platforms. These aims are not possible with other paper-based detectors, such as Raman spectroscopy and mass spectrometry. PP-XRD overcomes these limitations. Here we reported the simple and low-cost in situ PP-XRD protocol for phase identifications of inorganic and organic materials. We demonstrated that sample amounts of lead nitrate on paper substrate can be reduced into 1/30 of conventional ones by using the standard glass substrate at the same signal-to-noise ratio (S/N) of the X-ray diffraction (XRD) pattern. The paper-based method was comparable in sample quantity and intensity with zero background holder method, even though single crystal Si(100) substrate as zero background holder was used for the specimen preparation of CTAB (C 19 H 42 BrN). More importantly, paper substrates helped reduce preferred orientation that was generally present in routine powder XRD. Also, combined with paper chromatography , overlap peaks were eliminated in the XRD detection patterns of lead nitrate and cobalt nitrate hexahydrate. This new PP-XRD protocol may accelerate the process to identify phase or determine the molecular structures of new materials using trace sample directly. It also includes a hyphenated technique of powder XRD with a simple paper-based microfluidic separation of chemical solutions .
研究领域:
材料科学
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分析化学
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X射线衍射
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基于纸的设备
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微流控技术
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）