A self-assembling RNA aptamer-based graphene oxide sensor for the turn-on detection of theophylline in serum.
To date, few effective fluorescent biosensors based on RNA aptamers have been developed because the intrinsic instability of RNA in the presence of nucleases precludes the application of RNA aptamers for the analysis of biological fluids. In this study, we developed a simple, sensitive, selective turn-on fluorescent aptasensor for theophylline detection in serum, utilizing ligand-induced self-assembling RNA aptamers and two different interaction stages of the aptamer fragments with graphene oxide (GO). A single strand of the theophylline RNA aptamer (33-mer) was split at the end loop region into two shorter fragments, one of which was labeled with a fluorophore (FAM). In the absence of theophylline, the adsorption of the two individual fragments on GO brought the fluorophore in close proximity to the GO surface, resulting in highly efficient quenching of fluorescence. The system showed very low background fluorescence. Conversely, the fragments self-assembled into an RNA aptamer/theophylline complex and were dissociated from GO. The quenched fluorescence was significantly recovered, and theophylline could be detected at a wide range of concentrations from 1 to 100μM, with a detection limit of 0.155μM and good selectivity in serum. Moreover, because of the shorter RNA fragments and the effective protection ability of GO from nuclease cleavage, the RNA sequences remained stable during the experiments. This design may serve as an example for the application of RNA aptasensors in the clinical setting.
Institute of Respiratory Diseases, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, No. 1017 Dongmen North Road, Shenzhen 518020, China; Post-doctoral Research Station of Integrated Traditional Chinese and Western Medicine, School of Medicine, Jinan University, Guangzhou 510632, China; Shenzhen Institute of Geriatrics, Shenzhen 518020, China.
Kai
K
Ling
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Key Laboratory of Biomedical Material of Tianjin, Tianjin 300192, China.
Hongyan
H
Jiang
Institute of Respiratory Diseases, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, No. 1017 Dongmen North Road, Shenzhen 518020, China.
Yang
Y
Li
College of Medicine, Hunan Normal University, Changsha 410006, China.
Xiaojun
X
Tao
Institute of Respiratory Diseases, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, No. 1017 Dongmen North Road, Shenzhen 518020, China.
Chen
C
Qiu
Institute of Respiratory Diseases, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, No. 1017 Dongmen North Road, Shenzhen 518020, China. Electronic address: frli62@163.com.
Fu-Rong
FR
Li
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D001774:Blood Chemical Analysis / Q000295:instrumentation; D001993:Bronchodilator Agents / Q000097:blood; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013806:Theophylline / Q000097:blood*
D052157:Aptamers, Nucleotide; D001993:Bronchodilator Agents; D010087:Oxides; D006108:Graphite; D013806:Theophylline
Aptasensor; Fluorescence detection; Graphene oxide; Self-assembling strategy; Theophylline