SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Cheng Qin,Xinlan Bian,Wei Lv,Bingzhi Li
CRISPR/Cas12a-based biosensors typically output fluorescent, colorimetric, and electrochemical signals, relying on reporters that suffer from low sensitivity, high cost, and low stability. Herein, we introduced a label-free chemiluminescent (CL) reporting system based on a DNAzyme known as “Supernova”. Supernova catalyzes the translocation of phosphate from a 1,2-dioxetane substrate (specifically, CDP-Star) to its 5′-OH ends, thereby triggering a CL reaction that produces light. Upon activation by the target, Cas12a cleaves Supernova, rendering it inactive in reacting with CDP-Star. Without pre-amplification, this biosensor can detect synthetic DNA corresponding to the SARS-CoV-2 N gene and monkeypox virus (MPXV) F3L gene with detection limits (LOD) of 1.5 and 2.4 pM, respectively. Integration with pre-amplification further enables the detection of SARS-CoV-2 and MPXV genes down to 1 copy/μL in real samples. Furthermore, the application of this CL system was expanded to the detection of non-nucleic acids with the integration of ATP aptamers, resulting in improved sensitivity in ATP biosensing compared to fluorescent assays. Overall, this work represents the first development of a label-free CL Cas12a reporting system, demonstrating its enhanced performance and broad applicability in synthetic biology-enabled sensing technology.
研究领域:
生物传感技术
·
分子诊断学
·
合成生物学
✓ 已验证
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Kai Shi,Wenjie Luo,Ying Cheng,Honglei Li,Liai Peng,Xiangrui Luo,Yu Hu,Jiaheng Zhang,Jiaxuan Chen
CRISPR/Cas12a-powered biosensors with guanine (G)-rich sequence reporters (e.g., G-quadruplex and G-triplex) are widely used in detection applications due to their simplicity and sensitivity. However, when these biosensors are employed for molecular detection in complex samples, they may encounter difficulties such as high background signal and susceptibility to interference because of the “turn-off” signal output. Herein, we explore, for the first time, a set of phosphorothioate (ps)-modified G-quadruplex (G4) and G-triplex (G3) sequences that can bind with thioflavin T (ThT) in an active split CRISPR/Cas12a system (SCas12a) to generate a “turn-on” fluorescent signal. To apply this new phenomenon, we develop a universal SCas12a-powered biosensor for “turn-on” fluorescent detection of nucleic acid (miRNA-21) and non-nucleic acid (kanamycin) targets by using ps-modified hairpin G3 as a reporter (SCas12a/psHG3). Target recognition activates SCas12a’s trans-cleavage activity, leading to cleavage at the loop region of the psHG3 reporter. The released prelocked psG3 DNA binds ThT to produce a strong fluorescence signal. Without preamplification, this strategy can detect miRNA-21 with a detection limit of 100 fM. Moreover, the SCas12a/psHG3 system was further utilized for detecting kanamycin by incorporating its aptamers, enabling the detection of kanamycin at concentrations as low as 100 pM. This work is the first to develop a “turn-on” SCas12a/psHG3 system, showcasing its improved performance and wide range of applications in synthetic biology-based sensing technology.
研究领域:
生物技术
·
分子生物学
·
合成生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2024
·
IF 10.7
Xueying Lei,Lihua Ding,Xiaonan Yang,Feng Xu,Yongjun Wu,Songcheng Yu
The CRISPR/Cas12a system is increasingly used in biosensor development. However, high background signal and low sensitivity for the non-nucleic acid targets detection is challenging. Here, a p adlock activator which could i nhibit the t rans -cleavage activity of CRISPR/Cas12a system in the intact form by steric hindrance effect (PAIT effect) was designed for non-nucleic acid targets detection. The PAIT effect disappeared when padlock activator was separated into two split activators. To verify the feasibility of padlock activator, a Ca 2+ sensor was developed based on PAIT effect with the assistance of DNAzyme, activity of which was Ca 2+ dependent. In the presence of Ca 2+ , DNAzyme was activated to cleave its substrate, a padlock activator modified with adenine ribonucleotide, into split padlock activators which would trigger the trans -cleavage activity of Cas12a to generate fluorescence. There was a mathematical relationship between the fluorescence intensity and the logarithm of Ca 2+ concentration ranging from 10 pM to 1 nM, with a limit of detection of 3.98 pM. The little interference of Mg 2+ , Mn 2+ , Cd 2+ , Cu 2+ , Na + , Al 3+ , K + , Fe 2+ , and Fe 3+ indicated high selectivity. Recovery ranged from 93.32% to 103.28% with RSD s from 1.87% to 12.74% showed a good accuracy and reliability. Furthermore, the proposed sensor could be applied to detect Ca 2+ in mineral water, milk powder and urine. The results were consistent with that of flame atomic absorption spectroscopy. Thus, PAIT effect is valuable for expanding the application boundary of CRISPR/Cas12a system.
研究领域:
生物技术
·
生物化学
·
分析化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Chunyan Wang,Cuiyan Han,Xiaoxue Du,Weiwei Guo
In addition to their roles as revolutionary genome engineering tools, CRISPR-Cas systems are also highly promising candidates in the construction of biosensing systems and diagnostic devices, which have attracted significant attention recently. However, the CRISPR-Cas system cannot be directly applied in the sensing of non-nucleic acid targets, and the needs of synthesizing and storing different vulnerable guide RNA for different targets also increase the application and storage costs of relevant biosensing systems, and therefore restrict their widespread applications. To tackle these barriers, in this work, a versatile CRISPR-Cas12a-based biosensing platform was developed through the introduction of an enzyme-free and robust DNA reaction network, the entropy-driven dynamic DNA network. By programming the sequences of the system, the entropy-driven catalysis-based dynamic DNA network can respond to different types of targets, such as nucleic acids or proteins, and then activate the CRISPR-Cas12a to generate amplified signals. As a proof of concept, both nucleic acid targets (a DNA target with random sequence, T, and an RNA target, microRNA-21 (miR-21)) and a non-nucleic acid target (a protein target, thrombin) were chosen as model analytes to address the feasibility of the designed sensing platform, with detection limits at the pM level for the nucleic acid analytes (7.4 pM for the DNA target T and 25.5 pM for miR-21) and 0.4 nM for thrombin. In addition, the detection of miR-21 or thrombin in human serum samples further demonstrated the applicability of the proposed biosensing platform in real sample analysis.
研究领域:
生物技术
·
分子生物学
·
分析化学
·
诊断设备
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）