SENSORS AND ACTUATORS B-CHEMICAL
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2023
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IF 8.4
Feng Gong,Yixia Yang,Xiaoyun Shan,Zhiyou Tan,Jingjing Qian,Songbai Tian,Xinghu Ji,Zhike He
Digital analysis is an effective single-molecule detection method and has attracted extensive attention in the field of bioassays. However, most digital assays require microchambers for signal compartmentalization. Herein, we developed a microchamber-free and enzyme-free digital assay by labeling paramagnetic beads directly with ultrabright fluorescent microspheres . In this assay, a DNA sandwich analysis was firstly performed on the bead to label a fluorescent microsphere. Then, the beads were loaded on the glass slide to form a monolayer film for signal readout. The whole analysis process does not require the participation of enzymes and the preparation of microchambers, which greatly simplifies the experimental steps and saves the costs. Furthermore, by introducing non-enzymatic hybridization chain reaction (HCR) and biotinylated DNA-conjugated gold nanoparticles (Au NPs-Bio), the capture efficiency and analytical sensitivity were improved. As a proof of concept , single-stranded DNA (ssDNA) of SARS-CoV-2 fragment was chosen as a model, and a detection limit of 1.5 fM was achieved. Spiked and recovery experiments on human serum and saliva samples validated the good performance of the proposed digital assay in real biological samples. The proposed assay provides a facile way of signal generation and readout for digital analysis.
研究领域:
生物技术
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分子诊断
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医学检验
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产品关联
DOI
高影响因子
ACS Nano
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2024
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IF 15.8
Zhipan Wang,Aimin Ma,Yiping Chen
Multiple and ultrasensitive detection of pathogenic bacteria is critical but remains a challenge. Here, we introduce a digital assay for multiplexed and target DNA amplification-free detection of pathogenic bacteria using botryoidal-like fluorescent polystyrene dots (PS-dots), which were first prepared through the hybridization reaction between primer exchange reaction chains and polystyrene nanospheres that encapsulated polymer dots for signal preamplification. The pathogenic bacteria’s DNA was cleavaged by the argonaute (Ago) protein-mediated multiple and precise cleavage reactions, where the obtained target sequences bridged the magnetic beads (MBs) and botryoidal-like PS-dots via a hybridization reaction, and the fluorescent MB-botryoidal PS-dot complexes were utilized as digital probes based on colors and sizes for digital encoding. An artificial-intelligence-fluorescent microsphere counting algorithm was applied to identify and count the fluorescent MBs for digital readout. This digital assay combined the ultrabright botryoidal-like PS-dots with Clostridium butyricum Ago’s precise enzyme cleavage properties, achieving simultaneous detection of three pathogenic bacteria with a linearity range from 102 to 106 CFU/mL without target DNA amplification within 1.5 h. This digital assay has also been applied to detect aquatic and clinical samples with accepted accuracy (98%), which offers an avenue for a next-generation multiplexed digital platform for pathogenic bacteria analysis.
研究领域:
生物技术
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医学检验
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纳米技术
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2025
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IF 4.6
Mengmeng Wang,Li Zheng,Fan Sun,Qingdan Ye,Pei Liang,Kun Pang,Zihong Ye,Yufeng Wang
Aptamer sensors based on surface-enhanced Raman scattering (SERS) technology have demonstrated great potential in the ultrasensitive and rapid detection of Escherichia coli ( E. coli ). Herein, this paper presents a digital SERS aptamer sensor. This sensor integrates ordered nanoscale array synthesis technology and digital analysis technology, enabling highly sensitive and rapid bacterial quantification. The ordered monolayer gold nanosphere arrays (Au NS) can form uniform and dense “hot spots” on the silicon wafer due to their uniform spherical structures and narrow gaps. Moreover, digital SERS is adopted to further optimize the signal uniformity so as to achieve precise quantification. The sensor modules are combined together through base pairing. The aptamers labeled with Raman tags are detached from the complementary DNA due to the competition of the target substance, thus realizing the detection of E. coli . The digital SERS aptamer sensor has been verified to possess excellent selectivity and reproducibility. It has a wide dynamic linear detection range from 1.0 * 10 1 to 1.0 * 10 9 CFU/ml and a detection limit of 0.657 CFU/ml, maintaining excellent specificity even in the presence of mixed bacterial interference. The spiked recoveries in actual samples range from 98.80 % to 99.81 %. Leveraging different aptamers and digital analysis, the sensor holds promise for food safety and environmental monitoring applications.
研究领域:
生物技术
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食品安全
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环境监测
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2025
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IF 6.7
Feng Gong,Xiaoyun Shan,Kebing Yi,Ziwen Tang,Yimiao He,Fuxiang Zhou,Xinghu Ji,Zhike He
The detection of disease-related protein biomarkers plays a crucial role in the early diagnosis, treatment, and monitoring of diseases. The concentrations of protein biomarkers can vary significantly in different diseases or stages of the same disease. However, most of the existing analytical methods cannot simultaneously meet the requirements of high sensitivity and a wide dynamic range. Herein, we developed a digital and analog immunoassay method based on submicron magnetic beads and fluorescent microspheres. The digital analysis achieves a limit of detection as low as 46 fg/mL (1.8 fM) for IL-6, and the analog analysis has a wide dynamic range spanning from 0.2 pg/mL to 10 ng/mL. Furthermore, the analog analysis can be used to quickly and roughly assess higher concentration proteins via visual detection, and the practical application potential of this method was verified by the detection of alpha-fetoprotein in serum samples from 12 healthy individuals and hepatocellular carcinoma patients. The established method does not involve the use of enzymes or costly instruments, which greatly simplifies the experimental steps, shortens the experimental time, and reduces the experimental cost. In view of those advantages, the proposed method has great application prospects in point-of-care applications.
研究领域:
生物医学工程
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免疫学
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诊断学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2023
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IF 12.6
Chunyan Wang,Yaxing Zhang,Chang Liu,Siyu Gou,Shanjin Hu,Weiwei Guo
Point-of-care testing (POCT) platforms for microRNA (miRNA) detection have attracted considerable attention in recent years, due to the increasingly important role of miRNA as biomarkers for the diagnosis of many diseases, such as cancers. However, several limitations such as the requirement of enzyme-related amplification system, expensive preservation cost, sophisticated analysis instruments and tedious operations of conventional miRNA biosensing devices severely hinder their widespread applications. In this work, a portable and smart colorimetric analysis platform was developed by employing the ultrathin DNA-gold nanoparticle (AuNP) hybrid hydrogel film as the signaling unit and the enzyme-free entropy-driven dynamic DNA network (EDN) as the signal converter and amplification unit. By programming the DNA sequences of the EDN, the EDN could respond to a specific miRNA, with miRNA-155 or miRNA-21 as the model target, and release a converter DNA with amplified concentration to further trigger the release of AuNPs from the hydrogel film as a colorimetric signal output. To avoid the use of sophisticated spectral instruments, digital analysis based on primary three-color channel (R/G/B) was further introduced by using user-friendly camera and image processing software, and a detection limit at pM level was achieved. Moreover, by introducing H 2 O 2 -mediated AuNPs enlargement procedure in the colorimetric analysis platform, the detection limit for miRNA target could further be enhanced to fM level. The POCT platform is also portable and storable with a good storage stability for at least 45 days, suggesting its great potential in practical diagnosis applications.
研究领域:
生物技术
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纳米技术
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分析化学
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分子生物学
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医学诊断
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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）