Label-free fluorescent aptasensor for chloramphenicol based on hybridization chain reaction amplification and G-quadruplex/N-methyl mesoporphyrin IX complexation

Catalytic hairpin self-assembly amplification fluorescence detection of chloramphenicol based on cross-shaped DNA and UiO-66

A catalytic hairpin self-assembly (CHA) amplification method was developed for CAP detection based on cross-shaped DNA and UiO-66. MOF was used to quench the fluorescent signal of FAM labeled DNA. Cross-shaped DNA with four fluorophore group (FAM) was utilized to enhance the fluorescent intensity. CAP could open hairpin structure of H-apt and induce CHA reaction. The product of CHA hybridized with cross-shaped DNA, resulting its leaving from the surface of UiO-66 and recovery of fluorescent signal. The limit of detection (LOD) was low to 0.87 pM. This method had been successfully applied for the detection of CAP in actual samples. Importantly, the high sensitivity was attributed to the great amplification efficiency of CHA, strong fluorescent intensity of cross-shaped DNA structure and great fluorescent quenched efficiency of UiO-66.

Aptamer-Based fluorescent DNA biosensor in antibiotics detection

The inappropriate employment of antibiotics across diverse industries has engendered profound apprehensions concerning their cumulative presence within human bodies and food commodities. Consequently, many nations have instituted stringent measures limiting the admissible quantities of antibiotics in food items. Nonetheless, conventional techniques employed for antibiotic detection prove protracted and laborious, prompting a dire necessity for facile, expeditious, and uncomplicated detection methodologies. In this regard, aptamer-based fluorescent DNA biosensors (AFBs) have emerged as a sanguine panacea to surmount the limitations of traditional detection modalities. These ingenious biosensors harness the binding prowess of aptamers, singular strands of DNA/RNA, to selectively adhere to specific target antibiotics. Notably, the AFBs demonstrate unparalleled selectivity, affinity, and sensitivity in detecting antibiotics. This comprehensive review meticulously expounds upon the strides achieved in AFBs for antibiotic detection, particularly emphasizing the labeling modality and the innovative free-label approach. It also elucidates the design principles behind a diverse array of AFBs. Additionally, a succinct survey of signal amplification strategies deployed within these biosensors is provided. The central objective of this review is to apprise researchers from diverse disciplines of the contemporary trends in AFBs for antibiotic detection. By doing so, it aspires to instigate a concerted endeavor toward the development of heightened sensitivity and pioneering AFBs, thereby contributing to the perpetual advancement of antibiotic detection methodologies.