Upconversion nanoparticles based FRET aptasensor for rapid and ultrasenstive bacteria detection.
Pathogenic bacteria cause serious harm to human health, which calls for the development of advanced detection methods. Herein, we developed a novel detection platform based on fluorescence resonance energy transfer (FRET) for rapid, ultrasensitive and specific bacteria detection, where gold nanoparticles (AuNPs, acceptor) were conjugated with aptamers while upconversion nanoparticles (UCNPs, donor) were functionalized with corresponding complementary DNA (cDNA). The spectral overlap between UCNPs fluorescence emission and AuNPs absorption enables the occurrence of FRET when hybridizing the targeted aptamer and cDNA, causing upconversion fluorescence quenching. In the presence of target bacteria, the aptamers preferentially bind to bacteria forming a three-dimensional structure and thereby dissociate UCNPs-cDNA from AuNPs-aptamers, resulting in the recovery of upconversion fluorescence. Using the UCNPs based FRET aptasensor, we successfully detected Escherichia coli ATCC 8739 (as a model analyte) with a detection range of 5-106cfu/mL and detection limit of 3cfu/mL. The aptasensor was further used to detect E. coli in real food and water samples (e.g., tap/pond water, milk) within 20min. The novel UCNPs based FRET aptasensor could be used to detect a broad range of targets from whole cells to metal ions by using different aptamer sequences, holding great potential in environmental monitoring, medical diagnostics and food safety analysis.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
Birui
B
Jin
MOE Key Laboratory of Biomedical Information Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
Shurui
S
Wang
MOE Key Laboratory of Biomedical Information Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China. Electronic address: minlin@mail.xjtu.edu.cn.
Min
M
Lin
Key Laboratory of Space Nutrition and Food Engineering, China Astronauts Research and Training Center, Beijing 100094, PR China.
Ying
Y
Jin
Key Laboratory of Space Nutrition and Food Engineering, China Astronauts Research and Training Center, Beijing 100094, PR China.
Shujing
S
Zhang
MOE Key Laboratory of Biomedical Information Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
Xingye
X
Cui
MOE Key Laboratory of Biomedical Information Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
Yan
Y
Gong
Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710049, PR China.
Ang
A
Li
MOE Key Laboratory of Biomedical Information Engineering, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
Feng
F
Xu
Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China; MOE Key Laboratory for Multifunctional Materials and Structures, Xi'an Jiaotong University, Xi'an 710049, PR China.
Tian Jian
TJ
Lu
D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques; D018076:DNA, Complementary / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry / Q000302:isolation & purification*; D031541:Fluorescence Resonance Energy Transfer; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry
D052157:Aptamers, Nucleotide; D018076:DNA, Complementary; D006046:Gold
Aptamer; E. coli ATCC 8739; Gold nanoparticle; Microorganism detection; Upconversion nanoparticle