基于核酸适配体传感器的即时检测(POCT)技术

Aptamer-based Biosensors for Point-of-care Testing

即时检测(point-of-care testing,POCT)是一种检测成本低、检测速度快、准确度高、能自我采样获得临床诊断结果的新型诊断技术。该技术在临床诊断、病情监控与疫情防控等领域发挥了重要作用。核酸适配体是一种能够特异性识别多种靶标的分子探针,具有易合成、批间差异小、易实现信号放大等突出优势,是生物医学传感器中重要的分子识别元件。本文概述了核酸适配体探针的现有筛选方法和进展,总结了核酸适配体POCT传感器信号放大策略,着重介绍了各类核酸适配体传感器在POCT领域的应用现状,并对核酸适配体POCT传感器的发展前景进行了展望。

Point-of-care testing(POCT)is an innovative diagnostic technology that provides cost-effective and rapid analysis,as well as accurate diagnostics.It enables patients to obtain clinically relevant results through selftesting.This technology has played a vital role in clinical diagnosis,disease monitoring,and early detection of infectious diseases.Nucleic acid aptamers,which are molecular probes capable of specifically recognizing multiple targets,have emerged as valuable components in biomedical sensors for molecular recognition.They offer advantages such as easy synthesis,good stability,and signal amplification.In recent years,research on aptamer-based POCT technology has garnered widespread attention in the world.The key issues in current research include obtaining more high-affinity aptamers to meet the detection needs of various targets,improving detection sensitivity through signal amplification,and integrating with different sensors to meet the requirements of POCT products.In this review,we first briefly introduce the selection process and the targets used for systematic evolution of ligands by exponential enrichment(SELEX).We discuss new SELEX strategies that have been developed to improve the selection efficiency and enhance the affinity of aptamers.Furthermore,we analyze 4 commonly used signal amplification strategies in aptamer-based POCT sensors.Among these methods,nucleic acid signal amplification and self-assembly signal amplification techniques are commonly used due to their low cost and wide applicability.The combination of these two techniques has also been developed to improve detection sensitivity and shorten reaction time.Coupling aptamers with enzyme-based reactions is the simplest method to improve signal amplification in POCT sensors.Various nanomaterials,such as metal nanoparticles,graphene,carbon nanotubes,and metal-organic frameworks,are widely used to improve the detection sensitivity.The combination of multi-functional nanomaterials for signal amplification has also been introduced in this part.Additionally,we introduce a strategy that involves the use of aptamers to initiate the activation of CRISPRassociated proteins,resulting in the cleavage of DNA or RNA molecular beacons and leading to signal amplification.Furthermore,we also introduce the most recent advances in the development of various aptamerbased electrochemical sensors and optical sensors in the field of POCT.Aptamer-based electrochemical sensors offer advantages such as fast response,easy operation,and portability.In this part,we highlight a series of blood glucose meter based aptasensors used to quantify a variety of biomarkers.For the importance of research on continuous detection device,we review recent progress in the development of aptamer-based continues electrochemical testing devices.In aptamer-based optical POCT techniques,the recent development of colorimetry,lateral flow assay(LFA),fluorescence,surface-enhanced Raman scattering(SERS),surface plasmon resonance(SPR),and evanescent wave fiber optic sensors are introduced,with a focus on comparing the performance characteristics of each sensor.Finally,this review presents a summary and future challenges in the research and commercialization of aptamer-based POCT sensors.To simplify the aptamers selection process,it is crucial to invest in studying the molecular recognition mechanisms of aptamers and developing artificial intelligence-based methods for aptamer selection.Additionally,integrating aptamers with advanced sensor technologies like microfluidic chips and wearable devices can greatly enhance detection sensitivity and stability.From a commercial perspective,current aptamer-based POCT products mostly comprise fluorescent or colorimetric assay kits and lateral flow test strips.However,to garner more attention in the competitive POCT market,aptamer-based POCT sensors have an edge in small molecules detection and multi-channel detection.