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Wang X, Hu J, Chen C, Lu J, Liu C, Ning Y, Lu F. Berberine@AgNPs@Carboxylated chitosan hydrogel dressing with immunomodulatory and anti-biofilm properties promotes wound repair in drug-resistant bacterial infections. Int J Biol Macromol 2025; 315:144496. [PMID: 40409636 DOI: 10.1016/j.ijbiomac.2025.144496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2025] [Revised: 05/14/2025] [Accepted: 05/20/2025] [Indexed: 05/25/2025]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial strain resistant to multiple antibiotics frequently encountered in clinical settings. Excessive antibiotic use has increased bacterial resistance, leaving a lack of effective treatments for MRSA infections. MRSA often colonizes the surface of skin wounds, resulting in chronic inflammation and protracted wound healing. The biofilm formation hinders the complete eradication of the bacteria, exacerbating the local inflammatory response and impeding wound healing. This study presents an innovative methodology for managing MRSA-infected skin wounds. The novel immunomodulatory hydrogel composed of Berberine, silver nanoparticles (AgNPs), and carboxylated chitosan (designated as Ber@AgNPs@CHI hydrogel) demonstrates enhanced therapeutic efficacy in a murine model of MRSA skin infection. This hydrogel is effective in eradicating MRSA and preventing biofilm formation. Furthermore, it modulates the local immune microenvironment by facilitating the transition of macrophages from the M1 to M2 phenotype and increasing the production of vascular endothelial growth factor (VEGF). These actions collectively facilitate the progression of the wound from the inflammatory to the proliferative phase, enhancing the early stages of wound healing. Hence, this safe and effective hydrogel mediates wound healing from multiple perspectives and targets, providing a new potential avenue for treating persistent infected wounds caused by clinical MRSA.
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Affiliation(s)
- Xiaoqi Wang
- Department of integrated traditional Chinese and Western Medicine, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Jue Hu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Chunjing Chen
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Jun Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Chang Liu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China.
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China.
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Liu S, Lu F, Chen S, Ning Y. Graphene oxide-based fluorescent biosensors for pathogenic bacteria detection: A review. Anal Chim Acta 2025; 1337:343428. [PMID: 39800527 DOI: 10.1016/j.aca.2024.343428] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 11/13/2024] [Accepted: 11/14/2024] [Indexed: 05/02/2025]
Abstract
BACKGROUND Pathogenic bacteria are widespread in nature and can cause infections and various complications, thereby posing a severe risk to public health. Therefore, simple, rapid, sensitive, and cost-effective methods must be developed to detect pathogenic bacteria. Biosensors are prominent platforms for detecting pathogenic bacteria owing to their high sensitivity, specificity, repeatability, and stability. With the development of nanotechnology, graphene oxide (GO) has been increasingly introduced into the construction of fluorescent biosensors to enhance their performance owing to its unique physicochemical properties. RESULTS This review systematically summarizes the development of GO-based fluorescent biosensors for the detection of pathogenic bacteria. First, we introduce the functionalization and modification of GO. The design and signal amplification strategies for GO-based fluorescent biosensors are also discussed. Finally, we explore the challenges and new perspectives associated with this field, with the aim of facilitating the development of GO-based fluorescent sensing technologies to prevent the spread of multidrug-resistant bacteria. SIGNIFICANCE This review will aid in the development of high-performance biosensors for pathogenic bacterial assays.
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Affiliation(s)
- Shiwu Liu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Shanquan Chen
- Department of General Education, The School of Humanities and Social Science of the Chinese University of Hong Kong (Shenzhen Campus), Shenzhen, Guangdong, 518172, People's Republic of China.
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
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Wang X, Chen C, Hu J, Liu C, Ning Y, Lu F. Current strategies for monitoring and controlling bacterial biofilm formation on medical surfaces. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 282:116709. [PMID: 39024943 DOI: 10.1016/j.ecoenv.2024.116709] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 07/03/2024] [Accepted: 07/07/2024] [Indexed: 07/20/2024]
Abstract
Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.
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Affiliation(s)
- Xiaoqi Wang
- Department of integrated traditional Chinese and Western Medicine, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Chunjing Chen
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Jue Hu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Chang Liu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China.
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan 410208, People's Republic of China.
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4
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Mansouri S. Recent developments of (bio)-sensors for detection of main microbiological and non-biological pollutants in plastic bottled water samples: A critical review. Talanta 2024; 274:125962. [PMID: 38537355 DOI: 10.1016/j.talanta.2024.125962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 05/04/2024]
Abstract
The importance of water in all biological processes is undeniable. Ensuring access to clean and safe drinking water is crucial for maintaining sustainable water resources. To elaborate, the consumption of water of inadequate quality can have a repercussion on human health. Furthermore, according to the instability of tap water quality, the consumption rate of bottled water is increasing every day at the global level. Although most people believe bottled water is safe, it can also be contaminated by microbiological or chemical pollution, which can increase the risk of disease. Over the last decades, several conventional analytical tools applied to analyze the contamination of bottled water. On the other hand, some limitations restrict their application in this field. Therefore, biosensors, as emerging analytical method, attract tremendous attention for detection both microbial and chemical contamination of bottled water. Biosensors enjoy several facilities including selectivity, affordability, and sensitivity. In this review, the developed biosensors for analyzing contamination of bottled water were highlighted, as along with working strategies, pros and cons of studies. Challenges and prospects were also examined.
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Affiliation(s)
- Sofiene Mansouri
- Department of Biomedical Technology, College of Applied Medical Sciences in Al-Kharj, Prince Sattam bin Abdulaziz University, Al-Kharj, 11942, Saudi Arabia; University of Tunis El Manar, Higher Institute of Medical Technologies of Tunis, Laboratory of Biophysics and Medical Technologies, Tunis, Tunisia.
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5
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Zhao J, Guo Y, Ma X, Liu S, Sun C, Cai M, Chi Y, Xu K. The Application of Hybridization Chain Reaction in the Detection of Foodborne Pathogens. Foods 2023; 12:4067. [PMID: 38002125 PMCID: PMC10670596 DOI: 10.3390/foods12224067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/18/2023] [Accepted: 08/24/2023] [Indexed: 11/26/2023] Open
Abstract
Today, with the globalization of the food trade progressing, food safety continues to warrant widespread attention. Foodborne diseases caused by contaminated food, including foodborne pathogens, seriously threaten public health and the economy. This has led to the development of more sensitive and accurate methods for detecting pathogenic bacteria. Many signal amplification techniques have been used to improve the sensitivity of foodborne pathogen detection. Among them, hybridization chain reaction (HCR), an isothermal nucleic acid hybridization signal amplification technique, has received increasing attention due to its enzyme-free and isothermal characteristics, and pathogenic bacteria detection methods using HCR for signal amplification have experienced rapid development in the last five years. In this review, we first describe the development of detection technologies for food contaminants represented by pathogens and introduce the fundamental principles, classifications, and characteristics of HCR. Furthermore, we highlight the application of various biosensors based on HCR nucleic acid amplification technology in detecting foodborne pathogens. Lastly, we summarize and offer insights into the prospects of HCR technology and its application in pathogen detection.
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Affiliation(s)
- Jinbin Zhao
- School of Medicine, Hunan Normal University, Changsha 410013, China;
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Yulan Guo
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Xueer Ma
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Shitong Liu
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Chunmeng Sun
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Ming Cai
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Yuyang Chi
- Department of Nutrition and Food Hygiene, School of Public Health, Jilin University, Changchun 130021, China
| | - Kun Xu
- School of Medicine, Hunan Normal University, Changsha 410013, China;
- The Research Center of Reproduction and Translational Medicine of Hunan Province, Changsha 410013, China
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Liu S, Chen S, Tian L, He Q, Wang X, Lu F, Ning Y. A graphene-oxide-based fluorometric assay for norA gene transcription in MRSA using Nb.BbvCI-assisted target recycling and T7 exonuclease-triggered cascade dual recycling signal amplification. Talanta 2023; 259:124549. [PMID: 37062089 DOI: 10.1016/j.talanta.2023.124549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 03/05/2023] [Accepted: 04/10/2023] [Indexed: 04/18/2023]
Abstract
We describe a graphene oxide (GO)-based bioassay for the fluorometric determination of norA gene transcription (mRNA) in methicillin-resistant Staphylococcus aureus (MRSA). This approach is based on Nb.BbvCI-assisted target recycling (NATR) and T7 exonuclease (T7 Exo)-triggered cascade dual-recycling signal amplification (TTCDRSA). The system included GO, a capture probe (CP), an assistant probe (AP), two carboxyfluorescein (FAM)-labeled hairpins (HP1 and HP2), endonuclease Nb.BbvcI, and exonuclease T7. In the presence of a target, AP, together with the target RNA, can hybridise with CP via partial complementarity to one another and open its hairpin structure to form a triple complex that is recognised by Nb.BbvCI. Once the CP is cleaved, the released AP and target RNA can walk on the carboxylated graphene oxide (CGO) surface to bind with another CP which induces the next round of cleavage, accumulating many trigger probes (TPs). The TPs then activate TTCDRSA with the assistance of T7 Exo, HP1, and HP2 to produce large amounts of free FAMs. These free FAMs are repelled by GO and exhibit enhanced fluorescence signals at excitation/emission wavelengths of 480/514 nm. The limit of detection (LOD) of the bioassay was calculated to be 0.37 fM, and the linear range of the method ranged from 1 fM to 1 nM. More importantly, the bioassay also exhibited high sensitivity and selectivity for target RNA detection in real samples, which may open a new promising avenue for monitoring drug efflux and studying the mechanisms of drug actions.
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Affiliation(s)
- Shiwu Liu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Shanquan Chen
- Department of General Education, The School of Humanities and Social Science of the Chinese University of Hong Kong (Shenzhen Campus), Shenzhen, Guangdong, 518172, People's Republic of China
| | - Longzhi Tian
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Qizhi He
- School of Basic Medical Science, Changsha Medical University, Changsha, Hunan, 410219, People's Republic of China
| | - Xiaoqi Wang
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
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Wang X, Liu S, Xiao R, Hu J, Li L, Ning Y, Lu F. Graphene-oxide-based bioassay for the fluorometric determination of agrC gene transcription in methicillin-resistant Staphylococcus aureus that uses nicking-enzyme-assisted target recycling and a hybridization chain reaction. Talanta 2022; 250:123714. [PMID: 35779362 DOI: 10.1016/j.talanta.2022.123714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 06/18/2022] [Accepted: 06/23/2022] [Indexed: 10/17/2022]
Abstract
Herein, we report the development of a graphene-oxide-based (GO-based) fluorescent bioassay for determining agrC gene transcription (mRNA) in methicillin-resistant Staphylococcus aureus (MRSA). The design is based on nicking-enzyme-assisted (Nb.BbvcI-assisted) target recycling amplification (NATR) and a hybridization chain reaction (HCR). The system consists of a helper probe (HP), a molecular beacon (MB) probe, four hairpins, and endonuclease Nb.BbvcI, which plays a role in target recycling and signal amplification. In the absence of the target, all of the carboxyfluorescein-labeled (FAM-labeled) hairpins are adsorbed through π-stacking interactions onto the surface of GO, resulting in FAM signal quenching. When the target is added, three nucleic acid chains hybridize together to form a triple complex that is recognized by Nb.BbvCI. The MB probe is then cleaved by Nb.BbvCI to generate an HP/target complex and two new DNA fragments; the former is hybridized to another MB probe and enters the next round of reaction. The two newly reproduced DNA fragments induce a HCR with the assistance of hairpins 1-4 to create double-stranded DNA (dsDNA) products. These dsDNA products are repelled by GO and generate strong fluorescence at excitation/emission wavelengths of 480/514 nm. Importantly, synergy between FAM and the dsDNA-SYBR Green I duplex structure led to significantly amplified fluorescence and enhanced sensitivity. The bioassay showed a detection limit of 7.5 fM toward the target and a good linearity in the 10 fM to 100 pM range. The developed method was applied to monitor biofilm formation and study the mechanism of drug action, with satisfactory results obtained.
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Affiliation(s)
- Xiaoqi Wang
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Shiwu Liu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Rong Xiao
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Jue Hu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Ling Li
- Experimental Center of Molecular Biology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
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8
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Wang L, Hu M, Wang Y, Xi S, Cheng M, Niu L, Dong Y. Developing a three-input cascade DNA logic gate based on the biological characteristics of metal ion-GO, combined with analysis and verification. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:4955-4963. [PMID: 34633006 DOI: 10.1039/d1ay01309b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Due to the limitation of technology, electronic computing is approaching the limit of technology, and new computing tools need to be developed. Here, we build a three-input cascade logic gate based on the advantages of biomolecules, particularly DNA, in the construction of computational logic systems, combined with metal ions and graphene oxide (GO). It is worth mentioning that this study uses a variety of research methods. In addition to the commonly used biological experiments, NUPACK and visual DSD simulation methods are used for analysis, and orthogonal, standardized and other statistical means are used to simplify the experimental process and make the results intuitive. Finally, the designed three-input logic gate is successfully constructed, and it is found that it may have the potential to realize complex computing.
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Affiliation(s)
- Luhui Wang
- Department of Life Science, Shaanxi Normal University, Xi'an 710119, China.
| | - Mengyang Hu
- Department of Computer Science, Shaanxi Normal University, Xi'an 710119, China
| | - Yue Wang
- Department of Computer Science, Shaanxi Normal University, Xi'an 710119, China
| | - Sunfan Xi
- Department of Life Science, Shaanxi Normal University, Xi'an 710119, China.
| | - Meng Cheng
- Department of Life Science, Shaanxi Normal University, Xi'an 710119, China.
| | - Li Niu
- Basic Medical College, Shanxi Medical University, Taiyuan 030001, China
| | - Yafei Dong
- Department of Life Science, Shaanxi Normal University, Xi'an 710119, China.
- Department of Computer Science, Shaanxi Normal University, Xi'an 710119, China
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9
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He Q, Ma S, Wang J, Chen K, Dong J, Zhou J, Chen D, Ning Y. Graphene Oxide-Based Fluorometric Determination of the eta Gene in Pseudomonas aeruginosa Using Nicking Enzyme-Mediated Cyclic Signal Amplification. ANAL LETT 2021. [DOI: 10.1080/00032719.2021.1980885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Qizhi He
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- School of Basic Medical Science, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- Discipline of Basic Medical Application, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Shuheng Ma
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- Discipline of Basic Medical Application, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Jingya Wang
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Keke Chen
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Jun Dong
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- Discipline of Basic Medical Application, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Ji Zhou
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- School of Basic Medical Science, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Danna Chen
- Academician Workstation, Changsha Medical University, Changsha, Hunan, People’s Republic of China
- School of Basic Medical Science, Changsha Medical University, Changsha, Hunan, People’s Republic of China
| | - Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China
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Ning Y, Wang X, Hu J, Li L, Xiao R, Lu F. Graphene-based fluorometric determination of agrD gene transcription in methicillin-resistant Staphylococcus aureus using exonuclease III-aided target recycling and DNA walker cascade amplification. Mikrochim Acta 2021; 188:269. [PMID: 34297210 DOI: 10.1007/s00604-021-04933-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/08/2021] [Indexed: 11/30/2022]
Abstract
A graphene-based bioassay is described for the fluorometric determination of agrD gene transcription (mRNA) in methicillin-resistant Staphylococcus aureus (MRSA). This method includes exonuclease III (Exo III)-assisted target recycling and DNA walker cascade amplification. Hairpin1 (HP1) consists of a capture probe (CP) and DNA walker sequence. In the absence of the target, 5'-amino modified hairpin2 (HP2) labeled with carboxyfluorescein (FAM) at its 3' terminus is covalently linked to graphene via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) catalysis, resulting in the quenching of the FAM signal. The stem-loop structure of HP1 opens when the target is added to form partially complementary DNA/RNA hybrids. Exo III then initiates the target recycling process by cleaving the CP and DNA walker cascade reaction by automatic walking. This iterative reaction causes the FAM to dissociate from the graphene, and the fluorescence can be measured at excitation/emission wavelengths of 480/514 nm. Therefore, the target can be assayed by fluorescence. This method has a linear relationship with the concentration of target within the range 1 fM to 100 pM with a detection limit of 1 fM. The developed bioassay was used to monitor biofilm formation and investigate the mechanism of drug action with satisfactory results. Schematic representation of the graphene-based fluorescent bioassay for agrD gene transcription in methicillin-resistant Staphylococcus aureus by using exonuclease III-aided target recycling and DNA walker cascade amplification.
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Affiliation(s)
- Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Xiaoqi Wang
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Jue Hu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Ling Li
- Experimental Center of molecular biology, The Chinese Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Rong Xiao
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China
| | - Fangguo Lu
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, 410208, People's Republic of China.
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