TALANTA
·
2020
·
IF 5.339
Yuan-Yuan Jiang,Xu Zhao,Li-Jian Chen,Cheng Yang,Xue-Bo Yin,Xiu-Ping Yan
Serious ochratoxin A (OTA) contamination necessitates the development of rapid, sensitive and selective analytical methods for its determination in food safety. Herein, we report a persistent luminescence resonance energy transfer (LRET) based aptasensor for the autofluorescence-free detection of OTA. OTA aptamer functionalized persistent luminescence nanorod (PLNR) Zn 2 GeO 4 :Mn 2+ and the aptamer complementary DNA modified gold nanoparticle (AuNP) were used as the donor and the acceptor, respectively. The developed LRET aptasensor integrated the advantages of the long-lasting persistent luminescence of PLNR, the high selectivity of aptamer and the low probe background of LRET sensors, allowing autofluorescence-free detection of OTA in biological samples with high sensitivity and selectivity. The developed LRET aptasensor gave an excellent linearity in the range of 0.01–10 ng mL −1 , the detection limit of 3 pg mL −1 and the precision of 2.7% (RSD, n = 11) at 1 ng mL −1 level. The applicability of the developed aptasensor was demonstrated by analyzing beer samples for OTA with the recoveries of 92.3%–104%.
研究领域:
分析化学
·
食品安全
·
纳米技术
·
毒理学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2018
·
IF 8.173
Wei Chen,Chao Yan,Lin Cheng,Li Yao,Feng Xue,Jianguo Xu
In this paper, a novel ultrasensitive signal-on electrochemical aptasensor has been proposed for Ochratoxin A (OTA) assay based on DNA controlled layer-by-layer assembly of dual gold nanoparticle (AuNP) conjugates. To construct the aptasensor, the 1 st AuNP conjugate was prepared by simultaneous immobilization of the capture probe 2 (CP2) and bridge probe (BP) onto the AuNPs. Then, OTA aptamer was loaded onto 1 st AuNPs by hybridization with CP2. The 1 st AuNP conjugate can be further immobilized onto the electrode by hybridization between BP and capture probe 1 (CP1), which was pre-immobilized on Au electrode. The 2 nd AuNP conjugate was prepared by immobilization of ferrocene (Fc) tagged SH-signal probe (SSP). Due to the recognition between aptamer on 1 st AuNP conjugate and OTA, CP2 was reformed in the ssDNA state, which can be utilized as the anchor for immobilization of 2 nd AuNP conjugate for electrochemical signal reporting. Because of the high surface-to-volume ratio and good conductivity of AuNPs, this dual AuNPs assembled nanoarchitecture finally lead to greatly improved abilities to load a large number of Fc molecules and significantly amply the electrochemical response even at a low target concentration. Both qualitative and quantitative analysis of OTA were thus realized by differential pulse voltammetry (DPV) signals, resulting in an excellent detection limit of 0.001 ppb and a wide dynamic range from 0.001 to 500 ppb over 6 orders of magnitude. Moreover, the real sample analysis towards OTA spiked wine samples was favorable, implying a great potential for practical applications. We envision that this unique dual AuNP conjugate assembly strategy would pave a new avenue for the development of versatile signal amplified electrochemical aptasensors.
研究领域:
分析化学
·
纳米技术
·
食品安全
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Meng Xu,Yimeng Li,Xiaopeng Hu,Shuai Zhang,Yiwei Liu
A smartphone-assisted colorimetric aptasensor was constructed for the detection of ochratoxin A (OTA) utilizing Au/CeO₂/rGO nanohybrid. The sensor integrates aptamer-functionalized Au/Fe 3 O 4 (Apt/Au/Fe 3 O 4 ) as recognition elements. The complementary-chain-modified Au/CeO₂/rGO (cDNA/Au/CeO₂/rGO) act as nanozyme catalyst for signal amplification through the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to blue-colored ox-TMB. The detection mechanism relies on competitive binding between OTA and cDNA/Au/CeO 2 /rGO to Apt/Au/Fe 3 O 4 . Upon OTA introduction, OTA preferentially binds to Apt/Au/Fe 3 O 4 . These Apt/Au/Fe 3 O 4 are magnetically separated and introduced into the cDNA/Au/CeO 2 /rGO suspension. Unbound Apt/Au/Fe 3 O 4 interacts with cDNA/Au/CeO 2 /rGO. After magnetic separation, the residual cDNA/Au/CeO 2 /rGO concentration in supernatant exhibits a correlation with the OTA concentration. This design effectively eliminates potential interference from the intrinsic color of coffee, significantly improving the accuracy of colorimetric detection. The aptasensor demonstrated superior selectivity towards OTA with a detection limit of 27.3 pg mL −1 . This specificity was validated against interference, with recovery rates of 102.1–117.4 % in coffee, as confirmed by ELISA.
研究领域:
食品安全
·
分析化学
·
纳米技术
·
生物传感器
·
毒素检测
·
适配体技术
✓ 已验证
产品关联
DOI
高影响因子
FOOD CONTROL
·
2022
·
IF 6.652
Yujiao Hou,Nan Long,Boyu Jia,Xiaofang Liao,Minghan Yang,Lizhu Fu,Lidong Zhou,Ping Sheng,Weijun Kong
The prevalent ochratoxin A (OTA) contamination in food has increased the urgency to develop sensitive and accurate detection methods. This study reported a conveniently fabricated label-free electrochemical (EC) aptasensor for ultrasensitive detection of OTA based on the competitive binding of OTA with its specific aptamer without any signal amplification strategy. A gold electrode (AuE) was modified with a compact layer of double-stranded DNA (dsDNA), obtained via OTA aptamer and complementary DNA (cDNA) hybridization, to act as a barrier for redox probe [Fe(CN) 6 ] 3-/4- to AuE access. This led to a high initial electron-transfer resistance (R ct ), recorded via electrochemical impedance spectroscopy (EIS). Since the aptamer displayed a higher affinity to OTA than cDNA, the added OTA triggered aptamer dissociation from AuE to form the OTA-aptamer complex, obviously decreasing the R ct . The target-induced variation in the resistance response strongly depended on the OTA concentration. Optimum conditions improved the linear relationship between R ct and the logarithm of OTA concentration in a range of 0.05–10 ng/mL with a limit of detection (LOD) of 0.05 ng/mL for OTA. Recoveries of 74.8–105% with relative standard deviations (RSDs) of 8.86–13.09% were obtained in the spiked malt samples. The Real-world detection of OTA in the actual malt samples confirmed the reliability of the convenient, cost-effective, and highly specific impedimetric aptasensor, exhibiting significant promise for extended application in food control to identify more hazardous contaminants by altering the corresponding aptamers.
研究领域:
食品科学
·
分析化学
·
电化学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Anping Wang,Jianing Liu,Jinlan Yang,Li Yang
An aptamer affinity based microextraction column is developed to be directly in-line coupled to capillary electrophoresis-mass spectrometry (CE-MS) for analyzing mycotoxins in food samples. Single-stranded DNA aptamers for selective recognition of aflatoxin B1 (AFB1) and ochratoxin A (OTA) targets are co-immobilized via covalent bonds on the surface of the inlet end of a capillary, which is pre-modified with three-dimensional porous layer and gold nanoparticles to enhance the specific surface area and loading capacity. The outlet of the capillary is designed as a porous tip to serve as the spray source for injection to the mass spectrometry. All the necessary processes for pretreatment and analysis of a sample are accomplished in one injection, including aptamer affinity-based microextraction, CE separation and MS detection of analytes. AFB1 and OTA are simultaneously determined in a wide linear range with sample consumption of only 1 μL and the limit-of-detection as low as 1 pg/mL. The microextraction column exhibits excellent repeatability and stability, which can be used over 45 runs within a month with CE separation efficiency and only MS intensity slightly decreased. Mycotoxins in three kinds of cereal based infant foods are accurately analyzed using the proposed method. The study provides a robust and universal approach that would have potential applications in a variety of analytical fields based on selective molecular recognition coupling to CE-MS analysis.
研究领域:
分析化学
·
食品科学
·
质谱分析
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
·
2024
·
IF 2.3
Xin Wang,Xiaolei Zhao,Xinyi Song,Jinxing He
Ochratoxin A (OTA) is a toxic fungal metabolite that is commonly found in cereals and animal feed. It is economically damaging and potentially hazardous to human health. Herein, we propose an electrochemical immunosensor for the rapid detection of OTA using anti-OTA antibodies and diazonium-functionalized, screen-printed electrodes. We attached 4-aminobenzoic acid to an electrode surface, activated the carboxyl groups on the surface with carbodiimide, and attached an antibody to the diazo layer. Subsequently, we used bovine serum protein as a blocker to prevent non-specific antigens from binding to the antibody. We evaluated the performance of the sensor by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. The sensor is highly specific and sensitive, has good linear responses in the range 20–200 ng/mL, a limit of detection of 0.5 ng/mL, and good recoveries of 90.5%–100.9% in spiked samples. It can be stored at 4 °C for approximately 2 weeks, and is highly stable, with a current response variation of no more than 4.6%.
研究领域:
分析化学
·
食品科学
·
毒理学
·
传感器技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 45
·35448-35452
·
IF 3.84
Xuejuan Chen,Xiaojing Bai,Huiyan Li,Bailin Zhang
An aptamer-based microcantilever array sensor for detection of fumonisin B-1 (FB1) was developed. The sensing cantilevers in the array were functionalized with self-assembled monolayers (SAMs) of thiolated FB1-specific aptamer, while the reference cantilevers were modified with 6-mercapto-1-hexanol SAMs to eliminate interference from the environment by detecting the deflection induced by nonspecific interactions. This differential deflection amplitude between sensing and reference cantilevers shows a linearity relation with the concentration of FB1 in the range from 0.1 to 40 μg mL−1, with a limit of detection of 33 ng mL−1 (S/N = 3). The sensor exhibits good specificity over ochratoxin A (OTA) and deoxynivalenol (DON). This biosensor provides a promising approach to detect FB1 in food and agricultural products.
研究领域:
生物传感器
·
食品安全
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Yiqiong Chen,Xinyue Ding,Dandan Zhu,Xucong Lin,Zenghong Xie
Nonspecific adsorption is a challenge of specific recognition on aptamer-based affinity monoliths. Here, a novel highly hydrophilic polyhedral oligomeric silsesquioxane (POSS)-containing aptamer-based hybrid-silica affinity monolith with a good recognition nature was prepared and used for specific discrimination of ochratoxin A (OTA). A homogeneous polymerization mixture consisted of POSS chemicals, hydrophilic monomers and aptamer solution was directly polymerized via the “one-pot” method. Preparation and characterization of the resultant affinity monolith were studied in detail. A highly hydrophilic nature was obtained and the typical hydrophilic interaction liquid chromatography (HILIC) was observed when acetonitrile (ACN) content in mobile phase was 25%, which reached the highest hydrophilicity of POSS-based hybrid monoliths. By using OTA as model analyte, the nonspecific adsorption was effectively suppressed. The recovery of the analogue ochratoxin B (OTB) was only about 0.1% even if the content of OTB was 50 times more than OTA, which was much better than other POSS-containing monoliths and polar siloxane-based hybrid monoliths. Applied to beer samples, the adsorption of background materials was drastically resisted, and efficient recognition of OTA was obtained with the recoveries of 94.9–99.8%. Much less disturbance was observed than that occurred in hydrophobic POSS-based affinity monolith. It lights an attractive implement with high hydrophilicity and specificity for online selective recognition of OTA.
研究领域:
分析化学
·
食品科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 5
·1-9
·
IF 5.705
Yu Xinhui,Lin Yaohui,Wang Xusheng,Xu Liangjun,Wang Zongwen,Fu FengFu
An exonuclease-assisted multicolor aptasensor was developed for the visual detection of ochratoxin A (OTA). It is based on the etching of gold nanorods (AuNRs) mediated by a G-quadruplex-hemin DNAzyme. A DNA sequence (AG4-OTA) was designed that comprises a hemin aptamer and an OTA aptamer. OTA binds to AG4-OTA to form an antiparallel G-quadruplex, which halts its digestion by exonuclease I (Exo I) from the 3′-end of AG4-OTA. Thus, the retained hemin aptamer can bind to hemin to form a G-quadruplex-hemin DNAzyme. This DNAzyme has peroxidase-like activity that catalyzes the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H 2 O 2 to produce its diimine derivative (TMB 2+ ) in acidic solution. TMB 2+ can etch the AuNRs by oxidizing Au(0) into Au(I). This results in the generation of rainbow-like colors and provides a multicolor platform for the visual detection of OTA. The assay is based on the use of a single isolated aptamer and possesses obvious advantages such as multi-color visual inspection, relatively high sensitivity and accuracy. It can be used to detect as little as 30 nM concentrations of OTA by visual observation and even 10 nM concentrations by spectrophotometry. The method was successfully applied to the determination of OTA in spiked beer where it gave recoveries of 101–108%, with a relative standard deviation (RSD, n = 5) of <5%.
Schematic of an exonuclease-assisted multicolor bioassay based on the G-quadruplex-hemin DNAzyme-mediated etching of gold nanorods (AuNRs). It enables visual detection of ochratoxin A (OTA) with a detection limit of 30 nM.
研究领域:
分析化学
·
食品科学
·
纳米技术
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2021
·Vol. 188
·期 8
·1-9
·
IF 5.833
Chen Ruipeng,Li Shuang,Sun Yunfeng,Huo Bingyang,Xia Yating,Qin Yingkai,Li Shuning,Shi Baodi,He Defu,Liang Jun,Gao Zhixian
The design and fabrication of a surface-enhanced Raman scattering (SERS) aptasensor for simultaneous detection of zearalenone (ZEN) and ochratoxin A (OTA) in wheat and corn samples is described. The capture and reporter probes were SH-cDNA-modified gold nanorods and SH-Apt-modified Au@Ag core-shell nanoparticles, respectively. After recognizing OTA and ZEN aptamers and complementary strands (SH-cDNA), the reporter probe generated a strong SERS signal. The preferred binding of OTA and ZEN aptamers to OTA and ZEN, respectively, caused reporter probes to release the capture probes, resulting in a linear decrease in SERS intensity. The detection of OTA showed good linearity with an R 2 value of 0.986, which could be maintained across a wide concentration range (0.01 to 100 ng/mL), with the limit of detection of 0.018 ng/mL. For detection of ZEN, good linearity with an R 2 value of 0.987 could be maintained across a wide concentration range (0.05 to 500 ng/mL), with 0.054 ng/mL as the limit of detection. Good accuracy (relative standard deviation < 4.2%) during mycotoxin determination as well as excellent quantitative recoveries (96.0–110.7%) during the analysis of spiked real samples was achieved. The proposed SERS aptasensor exhibited excellent performance in the detection of OTA and ZEN in real food samples. Hence, by simply changing the aptamer, this new model can be applied to the detection of multiple mycotoxins in the food industry. Graphical abstract
研究领域:
分析化学
·
食品安全
·
纳米技术
·
毒理学
✓ 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）