Ultrasensitive Antibiotic Perceiving Based on Aptamer-Functionalized Ultraclean Graphene Field-Effect Transistor Biosensor

Abstract

Antibiotics are powerful tools to treat bacterial infections, but antibiotic pollution is becoming a severe threat to the effective treatment of human bacterial infections. The detection of antibiotics in water has been a crucial research area for bioassays in recent years. There is still an urgent need for a simple ultrasensitive detection approach to achieve accurate antibiotic detection at low concentrations. Herein, a field-effect transistor (FET)-based biosensor was developed using ultraclean graphene and an aptamer for ultrasensitive tetracycline detection. Using a newly designed camphor–rosin clean transfer (CRCT) scheme to prepare ultraclean graphene, the carrier mobility of the FET is found to be improved by more than 10 times compared with the FET prepared by the conventional PMMA transfer (CPT) method. Based on the FET, aptamer-functionalized transistor antibiotic biosensors were constructed and characterized. A dynamic detection range of 5 orders of magnitude, a sensitivity of 21.7 mV/decade, and a low detection limit of 100 fM are achieved for the CRCT-FET biosensors with good stability, which are much improved compared with the biosensor prepared by the CPT method. The antibiotic sensing and sensing performance enhancement mechanisms for the CRCT-FET biosensor were studied and analyzed based on experimental results and a biosensing model. Finally, the CRCT-FET biosensor was verified by detecting antibiotics in actual samples obtained from the entrances of Bohai Bay.

Aptamer-Modified Porous Anodized Aluminum Substrate for Rapid and Ultrasensitive Detection of Tetracycline via Surface Enhanced Raman Spectroscopy Couple with Electric Field Enrichment

“…The successful synthesis of the SERS sensor is confirmed by the strong enhancement of Raman signals (Scheme d). Apt-1 is a specific aptamer for TC, and Apt-2 is a complementary strand of Apt-1 . TC has high specific affinity for Apt-1.…”

“…Apt-1 is a specific aptamer for TC, and Apt-2 is a complementary strand of Apt-1. 31 Apt-1 has a highly specific binding and strong affinity to TC. However, Apt-2 is only bonded to Apt-1 by partial bases, so TC is more competitive than Apt-2.…”

Ultrasensitive Ratiometric Electrochemiluminescence Sensor with an Efficient Antifouling and Antibacterial Interface of PSBMA@SiO2-MXene for Oxytetracycline Trace Detection in the Marine Environment

“…Tetracycline antibiotics make up a class of important antibiotics with a tetracyclic skeleton, and oxytetracycline (OTC) is one of the tetracycline antibiotics. The residues caused by the overuse of OTC in aquaculture and animal husbandry pose a threat to environmental safety and human health. − Electrochemiluminescence (ECL) has been widely used in the fields of disease diagnosis, food detection, and environmental monitoring due to its high sensitivity, low background, wide linear range, and simple instrument . Therefore, it is necessary to develop an efficient antifouling ECL sensor to achieve accurate and sensitive detection of OTC. , …”

Rational Design of Trident Aptamer Scaffold for Rapid and Accurate Monitoring of 25-Hydroxyvitamin D3 Metabolism in Living Cells

“…Aptamers, obtained through the systematic evolution of ligands by exponential enrichment (SELEX) screening, are single-stranded DNA or RNA molecules that can bind tightly and specifically to target molecules. − Aptamer-based biosensors, which exhibit high sensitivity and simplicity, have been extensively developed to detect disease markers, including electrochemical, − localized surface plasmon resonance, and fluorescence sensors. , In 2017, Gu’s group developed the 25­(OH)­VD3 aptamers by SELEX, and the dissociation constants ( K d ) of the aptamer VDBA14 were determined to be 11 nM . Inspired by these encouraging developments, researchers are now focusing on developing more sensitive and reliable detection methods that allow the monitoring of 25­(OH)­VD3 biotransformation in cells. , However, using aptamer-based assays for detecting 25­(OH)­VD3 in living cells has limitations, including uneven distribution and inconsistent spatial orientation during immobilization, as well as impaired binding epitopes due to steric hindrance and random orientation. − Increasing immobilized aptamer numbers can help, but high density can lead to hindrance.…”