MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 8
·1-9
·
IF 6.232
Tang Juan,Li Jingjing,Xiong Pengyuan,Sun Yuanfang,Zeng Zhiyao,Tian Xiaochun,Tang Dianping
A photoelectrochemical (PEC) aptasensing platform is devised for sensitive detection of an organophosphorus pesticide based on dissolution of core-shell MnO 2 nanoflower@CdS (MnO 2 NF@CdS) by thiocholine (TCh). TCH is produced from the butyrylcholinesterase-acetylthiocholine system, accompanied by target-triggered rolling circle amplification (RCA). The core-shell MnO 2 NF@CdS with excellent PEC performance was synthesized and employed as a photo-sensing platform. The target was detected on a functionalized magnetic probe with the corresponding aptamer. Upon malathion introduction, the aptamer was detached from the magnetic beads, while capture DNA (cDNA, with primer fragment) remained on the beads. The primer fragment in cDNA can trigger the RCA reaction to form a long single-stranded DNA (ssDNA). Furthermore, a large number of butyrylcholinesterase (BChE) were assembled on the long ssDNA strands through the hybridization with the S 2 -Au-BChE probe. Thereafter, TCh generated from hydrolysis of ATCh by BChE can reduce MnO 2 NF (core) to Mn 2+ and release the CdS nanoparticles (shell) from the platform electrode, significantly enhancing the PEC signal. Under optimal conditions, the proposed aptasensor exhibited high sensitivity for malathion with a low detection limit of 0.68 pg mL −1 . Meanwhile, it also presents outstanding specificity, reproducibility, and stability. Importantly, the sensing platform provides a new concept for detection of pesticide.
Herein, this work devised a photoelectrochemical (PEC) aptasensing platform for sensitive detection of organophosphorus pesticide based on dissolution of core-shell MnO 2 nanoflower@CdS (MnO 2 NF@CdS) by the as-produced thiocholine (TCh) from the butyrylcholinesterase-acetylthiocholine system, accompanying with the target-triggered rolling circle amplification (RCA).
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BIOSENSORS & BIOELECTRONICS
·
2018
·
IF 8.173
Miao Zhong,Lu Yang,Hui Yang,Chang Cheng,Wenfang Deng,Yueming Tan,Qingji Xie,Shouzhuo Yao
We report here cadmium sulfide quantum dots (CdS QDs)-encapsulated metal-organic frameworks as signal-amplifying tags for ultrasensitive electrochemical detection of Escherichia coli O157:H7 ( E. coli O157:H7). CdS QDs were encapsulated in zeolitic imidazolate framework-8 (ZIF-8) to form CdS@ZIF-8 muti-core-shell particles by in situ growth of ZIF-8 in the presence of CdS QDs. To specifically recognize E. coli O157:H7 cells, CdS@ZIF-8 particles were coated with polyethyleneimine to introduce amino groups on their surfaces, followed by surface modification of anti- E. coli O157:H7 antibody. A sandwich-type electrochemical immunobiosensor for the detection of E. coli O157:H7 was fabricated using CdS@ZIF-8 particles as signal tags. Cd(II) ions were released from CdS@ZIF-8 tags by HCl leaching, enabling the detection of E. coli O157:H7 by differential pulse voltammetry . Under the optimized conditions, the linear range of the biosensor is from 10 to 10 8 colony forming units (CFU) per mL for E. coli O157:H7 detection, with the detection limit of 3 CFU mL −1 ( S / N = 3). The sensitivity of the biosensor for E. coli O157:H7 detection using CdS@ZIF-8 particles as signal tags is 16 times that of a biosensor using CdS QDs as signal tags, because the number of CdS QDs labeled to each bacterial cell increases greatly resulting from a great number of CdS QDs encapsulated in each CdS@ZIF-8 label. This method was successfully used to detect E. coli O157:H7 in milk samples.
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Analytical Methods
·
2017
·Vol. 10
·期 1
·51-58
·
IF 1.9
Xiao-Li Du,Tian-Fang Kang,Li-Ping Lu,Shui-Yuan Cheng
A novel electrochemiluminescence (ECL) biosensor based on CdSe@CdS quantum dots (QDs) functionalized MoS2 modified electrode was developed for sensitive detection of Pb(II) using HRP-mimicking DNAzyme biocatalytic precipitation (BCP) for ECL signal quenching. Polycationic poly(diallyldimethylammonium chloride) (PDDA) and negatively charged QDs were adsorbed on the surface of MoS2, in sequence, to form the MoS2–QDs composites, which were employed as a matrix for the immobilization of the G-rich DNA strand, i.e., T30695. The MoS2–QDs were characterized by UV-vis absorption spectroscopy, fluorescence spectroscopy, energy dispersive spectrometry, transmission electron microscopy, and field emission scanning electron microscopy. CdSe@CdS QDs can produce an ECL signal using 0.1 M K2S2O8 as a co-reactant. T30695 can combine with Pb(II) ions to form a stable parallel G-quadruplex. The G-quadruplex can further combine with hemin to form DNAzyme, which can catalyze H2O2 and oxidize 4-chloro-1-naphthol (4-CN) to produce an insoluble precipitation of benzo-4-chlorohexadienone on the surface of the sensor. When the concentration of Pb(II) in the solution was increased, more of DNAzyme was generated and subsequently more 4-CN molecules were oxidized catalytically, leading to a decrease of the ECL signal. Using this quenching strategy, the ECL signal of the biosensor was linearly dependent on the logarithm of the Pb(II) concentration ranging from 1.0 × 10−15 to 1.0 × 10−11 M with a detection limit of 0.98 f M. The stability and selectivity of the sensor were also investigated. The sensor was applied in the determination of Pb(II) in the real water samples and satisfactory results were obtained.
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TALANTA
·
2025
·
IF 6.1
Lijun Wang,Jiangchuan Tang,Shanshan Ren,Haixia Hu,Xiao Yang,Xianggui Chen
Although many colorimetric methods have been developed for on-site pesticide detection, most exhibit low sensitivity and limited resistance to interference. To address these issues, this study developed a novel dual-mode colorimetric-ratiometric fluorescence method for isocarbophos (ICP) detection using sulfur and nitrogen co-doped carbon nanodots (S, N-CDs) to inhibit catalytic Fe 3 O 4 @Cu-BTC nanozyme activity. The synthesized Fe 3 O 4 @Cu-BTC nanozymes with higher peroxidase-like activity were inhibited by S, N-CDs. The inhibitory mechanism was deeply investigated and was ascribed to (1) the restriction of the reaction between Fe 3 O 4 @Cu-BTC and hydrogen peroxide (H 2 O 2 ), which decreased the ·OH production, and (2) the ·OH scavenging ability of the S, N-CDs, forming the basis of the dual-mode method. The Fe 3 O 4 @Cu-BTC/Apt-complementary strand (CS)/S, N-CDs hybridization complexes demonstrated minimal to no peroxidase-like activity, preventing H 2 O 2 from oxidizing o -phenylenediamine (OPD) to produce yellow fluorescent 2,3-diaminophenazine (DAP). Meanwhile, the detection system demonstrated a low fluorescence intensity ratio (I 575 /I 465 ) at an excitation wavelength of 390 nm. However, the presence of ICP caused the CS/S, N-CDs to separate from the Fe 3 O 4 @Cu-BTC/Apt due to the high affinity between Apt and ICP. Then, the Fe 3 O 4 @Cu-BTC/Apt-ICP complexes recovered peroxidase-like activity, which promoted DAP production, accompanied by a pronounced fluorescence intensity ratio (I 575 /I 465 ). In optimum conditions, the detection limits (LODs) were 2.79 ng/mL (colorimetric) and 0.26 ng/mL (ratiometric fluorescence), respectively. The feasibility of the proposed method was verified via three spiked samples, yielding recovery rates of between 86.08 % and 112.64 %, indicating the significant potential for the highly sensitive, accurate on-site detection of ICP in actual samples.
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Analytical Methods
·
2024
·Vol. 16
·期 15
·2267-2277
·
IF 2.7
Yang He,Yangjie Li,Han Wang,Site Luo,Haihu Yu
The weakly bound organic ligand shells around perovskite quantum dots (QDs) are easily decomposed and cannot provide sufficient stability in polar solvents, which greatly obstructs their applications in sensing. Herein, a fluorescent sensor based on CsPbBr3/CdS core/shell QDs was developed for the detection of tetracycline (TC) in the polar solvent-ethanol. Pristine CsPbBr3 QDs were treated with cadmium diethyldithiocarbamate (Cd(DDTC)2) to form a shell on the surface at 110 °C, while extra oleylammonium bromide (OAmBr) was added to inhibit the phase transformation of CsPbBr3 into a Cs4PbBr6 impurity phase during high-temperature processing. And finally CsPbBr3/CdS core/shell QDs were successfully synthesized. The capping with the CdS inorganic shell remediated surface defects and improved the stability in ethanol without affecting the emission properties of the parent CsPbBr3 QDs. The results showed that the fluorescent sensor detected TC in the range of 0.05–25 μM with a low detection limit of 22.6 nM, whereas it had high selectivity and anti-interference ability for TC. And the fluorescence quenching mechanism of the sensor was mainly photoinduced electron transfer between TC and CsPbBr3/CdS QDs. Our research provides a unique way to improve the stability of perovskite QDs in polar solvents and applications in fluorescence detection.
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JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Fang Deng,Fei Zhong,Lina Zhao,Xubiao Luo,Shenglian Luo,Dionysios D. Dionysiou
Octahedral CdS/SnIn 4 S 8 nano-heterojunctions were fabricated by a facile and simple one-step in situ hydrothermal method, and the molar ratio of CdS to SnIn 4 S 8 was optimized. The optimal (0.5:1)CdS/SnIn 4 S 8 heterojunctions exhibit the highest visible-light photocatalytic activity with 97.1% degradation efficiency of 2-nitrophenol in 120 min, which is much higher than those of individual CdS and SnIn 4 S 8 . The enhanced photocatalytic performance could be attributed to the effective separation and transfer of photogenerated charges originating from the well-matched band gap structures. Of special significance is that (0.5:1)CdS/SnIn 4 S 8 can effectively mineralize 2-nitrophenol and real pharmaceutical wastewater. Moreover, CdS/SnIn 4 S 8 nano-heterojunctions show excellent reusability in five cycles due to the stable surface composition and chemical valence state.
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GREEN CHEMISTRY
·
2016
·Vol. 18
·期 12
·3628-3639
·
IF 8.506
Xiaofeng Ning,Sugang Meng,Xianliang Fu,Xiangju Ye,Shifu Chen
In this study, a nanoparticle structure of CdS with cubic phase (CdS-G) was prepared by a facile solid-state reaction at room temperature for the first time. CdS-G can be used as a highly active photocatalyst for selective oxidation of p-methoxybenzyl alcohol (pMBA) to p-methoxybenzaldehyde (pMBAD) and reduction of nitrobenzene (NB) to aniline (AL) in a coupled reaction system under green mild reaction conditions through visible light irradiation. Compared with the counterparts prepared by the conventional precipitation method (CdS-P) and hydrothermal method (CdS-H), the photocatalytic performance of CdS-G is greatly improved owing to the unique features of the nanostructure, the high surface area, pore volume, visible light absorption and photoelectric properties. The yield of pMBAD (AL) over CdS-G is about 1.6 (5.2) and 1.9 (20.8) times higher than that over CdS-P and CdS-H, respectively. The CdS-G sample exhibits excellent selectivity and stability because its valence band (VB) and conduction band (CB) positions matched well with the redox potentials of pMBA/pMBAD and NB/AL. Furthermore, the photogenerated holes and electrons can be efficiently and directly reacted with pMBA and NB, respectively. The photocatalytic selective oxidation and reduction reaction is a synergistic reaction via producing and consuming protons. The photogenerated holes and electrons could be utilized thoroughly to produce pMBAD and AL, respectively. The molar ratio of pMBA and NB was 3 : 1, and the yield of pMBAD and AL could be successfully achieved at a theoretical ratio of 1 : 1. This work highlights the promising scope for selective organic synthesis in one reaction system under mild conditions using photogenerated electrons and holes directly and simultaneously.
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CHEMICAL PHYSICS LETTERS
·
2017
·
IF 1.815
Shuning Liu,Chenchen Liu,Xinying Luan,Rui Yao,Yakai Feng
The far-red/near infrared photoluminescence of zinc phthalocyanines would be strongly quenched once they are aggregated, which will obviously hinder their wide applications in environmental, energy related and biomedical fields. Herein, the ultra-small sized semiconductor quantum dots with core-shell structures (CdSe@CdS) have been firstly synthesized and then assembled with a dendritic zinc phthalocyanine (ZnPc) in the H 2 O/DMF mixed solvent to obtain monodispersed nanospheres. Finally, it was found that the resultant ethanolic colloids can be employed as a sensitive and specific fluorescent nanoprobe for silver ions discrimination with a limit of detection (LOD) approaching to 10 − 8 mol/L.
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BIOSENSORS & BIOELECTRONICS
·
2012
·
IF 5.602
Jing Wang,Wei-Wei Zhao,Hong Zhou,Jing-Juan Xu,Hong-Yuan Chen
In this work, we firstly enunciated the presence of synergy effect between the electron and energy transfer in an electrochemiluminescence (ECL) system involving the CdS NCs and Au NPs, based on which an amplified ECL biosensor was constructed for sensitive detection of DNA–protein interactions. Specifically, Au NPs modified on electrode, following by assembled probe DNA . Then the modified GCE was hybridized with SiO 2 @CdS/DNA conjugates. With DNA duplex as a rigid spacer, Au NPs could not only accelerate the electron transfer but also produce the surface plasma resonance upon excited ECL of CdS NCs. However, the enhanced ECL could be greatly suppressed by the binding of target protein. The prepared biosensor possesses excellent analytical performance with the linear range of target protein from 0.015 to 150 nM.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2013
·Vol. 15
·期 8
·1-11
·
IF 2.175
Zhang Qiang,Cao Yongqiang,Shen Jianxing,Yang Ping
Nearly monodisperse CdSe/CdS and CdSe/Cd
x
Zn 1− x
S core–shell quantum dots (QDs) were synthesized by the epitaxial growth of CdS or Cd
x
Zn 1– x
S shells on pre-synthesized CdSe cores through a facile organic route. The thickness effect of CdS and Cd
x
Zn 1− x
S shells on the properties of resulting core–shell QDs, such as the photoluminescence (PL) efficiency, PL full width at half-maximum (fwhm), and PL decay lifetime, were investigated. The PL efficiency is greatly enhanced from 9 % of CdSe cores to 64 % of CdSe/Cd
x
Zn 1− x
S core–shell QDs. The PL spectra are narrowed after coating (fwhm ~28–32 nm). The alloy Cd
x
Zn 1− x
S shell is especially effective to enhance the PL efficiency, and it leads to a smaller red-shift in PL spectra compared with that of the CdS shell. The water-soluble CdSe/Cd
x
Zn 1− x
S core–shell QDs were obtained by the encapsulation of amphiphilic poly(styrene-co-maleic anhydride) (PSMA)–ethanolamine (EA) polymers, which was initially dispersed in oil phase. It was found that the CdSe/Cd
x
Zn 1− x
S QDs in water still retained a high PL efficiency as well as a small value in fwhm after encapsulating the CdSe/Cd
x
Zn 1− x
S QDs with PSMA–EA polymers, expanding the applications of these core–shell QDs in aqueous environment.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Jing Wang,Na Li,Feng Shao,Heyou Han
Highly luminescent, good stable and low toxic N-acetyl- l -cysteine (NAC) capped CdTe/CdS@ZnS–SiO 2 near-infrared (NIR)-emitting quantum dots (QDs) were successfully fabricated in aqueous solution via a microwave irradiation reduction route, in which thiol-capped CdTe/CdS QDs were employed as core templates and ZnCl 2 , NAC and tetraethyl orthosilicate as shell precursors. This presented ZnS-like clusters filled hybrid SiO 2 model not only greatly improved the brightness and stability of original CdTe/CdS QDs, but also tremendously decreased the cytotoxicity towards HeLa cells. Furthermore, it was found that Hg 2+ could effectively selective quench the QD NIR emission based on electron transfer process. On the basis of this fact, a simple, rapid and specific method for trace Hg 2+ determination was proposed. Under optimal conditions, the fluorescence intensity decreased linearly with the concentration of Hg 2+ ranging from 5.0 × 10 −9 to 1.0 × 10 −6 M and the limit of detection for Hg 2+ was 1.0 × 10 −9 M ( S / N = 3). As practical applications, the novel NIR sensor has been demonstrated to monitor and image Hg 2+ level in milk power and HeLa cells respectively with satisfactory results obtained.
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APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Ying Du,Linfei Li,Yanting Tang,Juan Li,Quanhui Guo,Guikuan Yue
With the production and application of antibiotics, the generated substandard antibiotic wastewater has brought unprecedented damage to the environment and finally the health of human beings. To alleviate this problem, photocatalytic degradation was proposed, and various catalysts have been developed with high efficiency and low cost. Herein, a novel 0D/3D/2D dual Z-heterojunction photocatalyst CdS QDs/Bi 2 WO 6 /g-C 3 N 4 was constructed by in-situ growth method in order to efficiently degrade multiple antibiotic pollutants. The combination of multi-dimensional materials is more conducive to the close contact between materials and the effective transport of photogenerated carriers. Results reveal that the sample of 75 %CdS QDs/Bi 2 WO 6 /g-C 3 N 4 (denoted as 0.75CSBC) showed the best degradation activity and stability for tetracycline (TC), and the degradation rate could reach 80.83 % within 12 min under visible light irradiation. Based on the detailed analysis of the results from free radical trapping experiment, Mott-Schottky test and liquid chromatography-mass spectrometry (LC-MS) test, the photocatalytic degradation mechanism and pathway were proposed. Besides, 0.75CSBC showed excellent degradation activity for levofloxacin (LVFX), oxytetracycline hydrochloride (OTC) and norfloxacin (NFLX), confirming its good universality. The multi-dimensional dual Z-heterojunction photocatalyst not only provides more active sites but also promotes the efficient migration of photogenerated charge, together with an excellent stability, indicating its wide practical application in the field of photocatalytic wastewater treatment. This work also provides an interesting method for the preparation of multi-dimensional heterogeneous catalysts.
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