Electrochemical biosensors for point-of-care testing

Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.

Wave-shaped microfluidic chip assisted point-of-care testing for accurate and rapid diagnosis of infections

Background:Early diagnosis and classification of infections increase the cure rate while decreasing complications,which is significant for severe infections,especially for war surgery.However,traditional methods rely on laborious operations and bulky devices.On the other hand,point-of-care(POC)methods suffer from limited robustness and accuracy.Therefore,it is of urgent demand to develop POC devices for rapid and accurate diagnosis of infections to fulfill on-site militarized requirements.Methods:We developed a wave-shaped microfluidic chip(WMC)assisted multiplexed detection platform(WMC-MDP).WMC-MDP reduces detection time and improves repeatability through premixing of the samples and reaction of the reagents.We further combined the detection platform with the streptavidin–biotin(SA-B)amplified system to enhance the sensitivity while using chemiluminescence(CL)intensity as signal readout.We realized simultaneous detection of C-reactive protein(CRP),procalcitonin(PCT),and interleukin-6(IL-6)on the detection platform and evaluated the sensitivity,linear range,selectivity,and repeatability.Finally,we finished detecting 15 samples from volunteers and compared the results with commercial ELISA kits.Results:Detection of CRP,PCT,and IL-6 exhibited good linear relationships between CL intensities and concentrations in the range of 1.25–40μg/ml,0.4–12.8 ng/ml,and 50–1600 pg/ml,respectively.The limit of detection of CRP,PCT,and IL-6 were 0.54μg/ml,0.11 ng/ml,and 16.25 pg/ml,respectively.WMC-MDP is capable of good adequate selectivity and repeatability.The whole detection procedure takes only 22 min that meets the requirements of a POC device.Results of 15 samples from volunteers were consistent with the results detected by commercial ELISA kits.Conclusions:WMC-MDP allows simultaneous,rapid,and sensitive detection of CRP,PCT,and IL-6 with satisfactory selectivity and repeatability,requiring minimal manipulation.However,WMC-MDP takes advantage of being a microfluidic device showing the coefficients of variation less than 10%enabling WMC-MDP to be a type of point-of-care testing(POCT).Therefore,WMC-MDP provides a promising alternative to POCT of multiple biomarkers.We believe the practical application of WMC-MDP in militarized fields will revolutionize infection diagnosis for soldiers.

A smartphone-based automated fluorescence analysis system for point-of-care testing of Hg(Ⅱ)

This work demonstrates a smartphone-based automated fluorescence analysis system(SAFAS)for point-of-care testing(POCT)of Hg(Ⅱ).This system consists of three modules.The smartphone module is used to provide an excitation light source,and to collect and analyze fluorescent images.The dark box module is applied to integrate the desired optical elements and offers a dark environment.The cost of the integrated dark box mainly includes the upper cover,box body,lower bottom,¯xture and some optical elements which is about$109.The chip module is used for fluorescence sensing,which is composed of an upper plate,bottom plate and cloth-based chip.Due to the integration of multiple smartphone functions,the SAFAS eliminates the need for additional power sources,light sources and analysis systems.The dark box and upper and bottom plates are made by 3D printer.The cloth-based chip(about$0.005 for each chip)is fabricated using the wax screenprinting technique,with no need for expensive and complex fabrication equipments.To our knowledge,the cloth-based microfluidic fluorescence detection method combined with smartphone functions is first reported.By using optimal conditions,the designed system can realize the quantitative detection of Hg(Ⅱ),which has a linear range of 0.001–100μgmL^(-1)and a detection limit of 0.5 ngmL^(-1).Additionally,the SAFAS has been successfully applied for detecting Hg(Ⅱ)in actual water samples,with recoveries of 100.1%–111%,RSDs of 3.88%–9.74%,and fast detection time of about 1 min.Obviously,the proposed SAFAS has the advantages of high sensitivity,wide dynamic range,acceptable reproducibility,good stability and low cost.Therefore,it is believed that the presented SAFAS has great potential to perform the POCT of Hg(II)in different water samples.

Point-of-Care Testing Using Three Dimensional Optical Biosensor Based on Microfluidic Technology

We have presented a three dimensional optical protein chip that fulfills the demanding for point-of-care diagnostics in terms of ease-of-use (one step assay), miniaturization (5 μl). The artful combination of magnetic nanoparticles on chip and total internal reflection imaging (TIRI) technology permits the sensitive and rapid detection of hs-CRP (high-sensitivity C-reactive protein). The whole test was complete within 10 min using “all in one step” assay with a limit of detection of 0.1 ng/mL hs-CRP. The measuring range for hs-CRP could be extended to 10 ng/mL. The chip can also be used to detect more parameters in blood samples.

Point-of-Care Testing vs. Laboratory Testing during High Patient Volume Situations

Introduction: Our aim was to determine what patient volume, if any, in-laboratory testing provides results faster than Point-of-Care-Testing (POCT). Methods: To evaluate POCT effectiveness during high volume situations, POCT was compared to in-laboratory testing during busy periods with large numbers of patients. Our setting was an urban level 1 trauma center with an academic emergency medicine department (ED) and annual patient volume of 70,000. Patients seen requiring laboratory testing during peak volume between 11 a.m. and 7 p.m. were enrolled over a five-week period. One tube of blood was sent to the laboratory and the other tube was run in the ED using POCT. Turnaround time was recorded as time from when the tube was received to when the result was available. We also completed a time-motion study to assess the number of POCT machines that would be needed to process the entire average hourly hospital laboratory volume. Results: We collected 539 hematology and chemistry specimens. The POCT group was significantly faster than in-laboratory testing, with mean POCT [complete blood count (CBC) and chemistry] 3.5 minutes compared to in-laboratory CBC test time of 30.9 minutes and chemistry test time of 55 minutes. As the volume of samples peaked, there was a slight but insignificant decrease in POCT turnaround time. If POCT was used to process the entire average hospital laboratory volume which approached 54 samples an hour, 3 POCT machines would be necessary to maintain turnaround times. Conclusion: Even during ED high volume situations, POCT provided results significantly faster than in-laboratory testing.

A Point-of-Care Test System for Biochemical Blood Analysis Based on ADUC824

A point-of-care test system has been studied in this paper.It was used to determine substances in blood such as Hemoglobin (HB),Aspartate Aminotransferase (AST),Creatine Kinase (CK) and so on.Based on the principle of amperometric determination,the research on detecting weak current signals was carried on.At the same time as to the weak signals (nA level),magnifying,sampling and processing the signals were also studied.Controlled by ADUC824 and assisted by other units, every substance could be determined automatically and rapidly integrated with the corresponding biosensor.In the experiment, the minimum detectable current of the instrument (YT2005-1) is 0.2 nA.With regard to the 1 nA which the experiment demanded,it could be up to the mustard.And the system can provide results in 180 s with a long term stability.

CeFe nanofibrous carbon nanozyme integrated with smartphone for the point-of-care testing of norfloxacin in water

The overuse of antibiotics has led to the severe contamination of water bodies,posing a considerable hazard to human health.Therefore,the development of an accurate and rapid point-of-care testing(POCT)platform for the quantitative detection of antibiotics is necessary.In this study,Cerium oxide(CeO_(2))and Ferrosoferric oxide(Fe_(3)O_(4))nanoparticles were simultaneously encapsulated into N-doped nanofibrous carbon microspheres to form of a novel nanozyme(CeFe-NCMzyme)with a porous structure,high surface area,and N-doped carbon material properties,leading to a considerable enhancement of the peroxidase(POD)-like activity compared with that of the CeO_(2)or Fe3O4 nanoparticles alone.The POD-like activity of CeFe-NCMzyme can be quenched using L-Cysteine(Cys)and subsequently restored by the addition of a quinolone antibiotic(norfloxacin,NOR).Therefore,CeFe-NCMzyme was used as a colorimetric sensor to detect NOR via an“On-Off”model of POD-like activity.The sensor possessed a wide linear range of 0.05–20.0μM(R^(2)=0.9910)with a detection limit of 35.70 nM.Furthermore,a smartphone-assisted POCT platform with CeFe-NCMzyme was fabricated for quantitative detection of NOR based on RGB analysis.With the use of the POCT platform,a linear range of 0.1–20.0μM and a detection limit of 54.10 nM were obtained.The spiked recoveries in the water samples were ranged from 97.73%to 102.01%,and the sensor exhibited good accuracy and acceptable reliability.This study provides a portable POCT platform for the on-site and quantitative monitoring of quinolone antibiotics in real samples,particularly in resource-constrained settings.

Point-of-care ultrasound for critically-ill patients: A mini-review of key diagnostic features and protocols

Point-of-care ultrasonography(POCUS)for managing critically ill patients is increasingly performed by intensivists or emergency physicians.Results of needs surveys among intensivists reveal emphasis on basic cardiac,lung and abdominal ultrasound,which are the commonest POCUS modalities in the intensive care unit.We therefore aim to describe the key diagnostic features of basic cardiac,lung and abdominal ultrasound as practised by intensivists or emergency physicians in terms of accuracy(sensitivity,specificity),clinical utility and limitations.We also aim to explore POCUS protocols that integrate basic cardiac,lung and abdominal ultrasound,and highlight areas for future research.

Recent progress on rapid diagnosis of COVID-19 by point-of-care testing platforms

The outbreak of COVID-19 has drawn great attention around the world.SARS-CoV-2 is a highly infectious virus with occult transmission by many mutations and a long incubation period.In particular,the emergence of asymptomatic infections has made the epidemic even more severe.Therefore,early diagnosis and timely management of suspected cases are essential measures to control the spread of the virus.Developing simple,portable,and accurate diagnostic techniques for SARS-CoV-2 is the key to epidemic prevention.The advantages of point-of-care testing technology make it play an increasingly important role in viral detection and screening.This review summarizes the point-of-care testing platforms developed by nucleic acid detection,immunological detection,and nanomaterial-based biosensors detection.Furthermore,this paper provides a prospect for designing future highly accurate,cheap,and convenient SARS-CoV-2 diagnostic technology.

Sweat-Based in Vitro Diagnostics(IVD):From Sample Collection to Point-of-Care Testing(POCT)

Sweat-based diagnostics offer an exciting avenue to noninvasively monitor analytes which had previously only been avail-able through painful blood draws.Sweat is enriched with physiologically valuable information,and recent proteomic studies have identified numerous critical analytes which have highly correlated levels in blood,interstitial fluid and sweat.How-ever,usage of sweat for health monitoring has not been studied extensively due to the substantial challenge of assembling a composite clinic-ready device.Recent advances in soft electronics have made this goal realizable,as these devices can perform electronic or optical monitoring on a flexible substrate using small volumes of liquid.While this field is still in its infancy,this review examines the physiological composition of sweat,various improvements in material science that improve sensor design,existing FDA approvals,methods of extracting sweat and comparisons to blood-based tests.Furthermore,this review assesses the critical challenges which must be overcome for this type of technology to make it out of research laboratories and into continuous clinical use.We believe that once properly harnessed,sweat-based diagnostics can provide patients a painless monitoring tool which can be customized to track a wide variety of medical conditions from the comfort of a patient’s own home.

POCT血糖仪和生化分析仪对血糖检测的比对研究

目的分析POCT血糖仪与生化分析仪对血糖检测结果,探讨POCT血糖仪检测糖尿病的临床应用价值。方法选取2016年11月至2017年11月该院100例患者,同时采用生化分析仪和2台不同型号的POCT血糖仪检测患者血糖,比较2种仪器的检测结果及相关性。结果 2台POCT血糖仪均达到国家标准和ISO15197:2013版标准,总符合率均大于95%。配对t检验显示2种型号的POCT血糖仪与生化分析仪的检测结果比较,差异均无统计学意义(P>0.05),且相关系数均大于0.98,表明相关性良好。结论 2种型号的POCT血糖仪与生化分析仪相关性良好,但POCT血糖仪操作更简便、迅速。

芯片实验室技术在POCT上的最新进展

芯片实验室在临床诊断,特别是在床边诊断(POCT)检验领域具有重要作用。介绍了芯片实验室技术在POCT领域,尤其是近两年来在核酸、蛋白质及细胞检测等方面的最新研究进展,以及纳米技术和传统技术如免疫层析试纸条技术融合后,芯片实验室在POCT领域所显示出的优势。对芯片实验室技术未来在POCT领域的发展方向进行了讨论。

25台POCT血糖仪与全自动生化分析仪血糖测定结果比对分析

目的：定期监测全院25台床旁检验血糖仪（以下简称POCT血糖仪）检测结果与贝克曼生化分析仪血糖测定结果的一致性,全面了解医院各病区血糖测定值之间的差异。方法：挑选10位空腹血糖在3.34～23.4 mmol/L（生化分析仪血糖检测结果）的患者,分别抽取EDTA抗凝全血和未抗凝血。EDTA抗凝血在POCT血糖仪测定血糖;不抗凝血在贝克曼DXC800生化分析仪测定血清葡萄糖,每份样本测定3次,取均值。经比对,21台POCT血糖仪与生化分析仪测定值偏倚〈20%。对21台仪器按使用年限编号排序,按规则抽样5台,用卫生部POCT血糖室间质评物测定血糖,与卫生部临床检验中心室间质评回报结果的靶值比对,计算偏倚。结果：POCT血糖仪测定结果与生化分析仪测定结果比对,21台偏倚在1.1%～13.1%范围,4台仪器分别有3-4个浓度的测定值偏倚〉20%（偏倚b ias22%～25%）。21台POCT血糖仪测定值变异系数（CV%）为3.4%～8.5%。抽样的5台POCT血糖仪与卫生部临床检验中心POCT血糖室间质评靶值（以下简称＂靶值＂）的偏倚为0～11.4%。结论：25台POCT血糖仪中21台与生化分析仪血糖检测结果比对具有一致性,4台比对差异大。生化分析仪比POCT血糖仪检测结果偏高约7.2%-13.1%。抽样的5台POCT血糖仪与靶值之间的偏倚符合卫生部临床检验中心质评判定标准。

POCT质量管理体系建设方案与成效分析

针对POCT质量管理系统缺陷问题,某三级医院建立了院内POCT质量管理体系,包括POCT管理架构、相关制度与流程、资质与授权、质量控制等方面。该体系专业性与科学管理并重,并借助信息化手段,实施完善的设备准入、结果报告与危急值管理。经实施,达到了流程简化、节约成本、平衡安全与便利的效果。下一步将对多种POCT检测项目进行信息化管理。

两种POCT法测定血HCG的比对研究

目的分析金标斑点POCT法和免疫荧光POCT法检测血HCG的性能。方法将306例样本按照浓度从低到高分为6个组,第1组86例、第2组60例、第3组14例、第4组68例、第5组41例、第6组37例。用电化学发光法（ECLIA）、金标斑点POCT法、免疫荧光POCT法平行检测这6个组的血HCG浓度。以ECLIA法为标准对金标斑点POCT法和免疫荧光POCT法的结果进行配对资料的t检验。结果 （1）免疫荧光POCT法的比对：第1组样本,免疫荧光POCT法和ECLIA法的符合性好;2～5组样本,免疫荧光POCT法和ECLIA法的检测结果比较差异无统计学意义;第6组样本,免疫荧光POCT法和ECLIA法的检测结果的差异有统计学意义（P〈0.05）。（2）金标斑点POCT法的比对：1～2组样本,金标斑点POCT法和ECLIA法的符合性好;3～4组样本,金标斑点POCT法和ECLIA法的检测结果比较差异有统计学意义。结论免疫荧光POCT法能简便、快速、准确的检测血HCG的浓度,且检测的准确度比金标斑点POCT法好,检测的量程比金标斑点POCT法宽。免疫荧光POCT法更适合于目前各类医院血HCG的急诊检验。

检验科体液组常见一些POCT项目的检测现状及质量控制管理

目前检验科体液组所开展一些胶体金法的POCT项目,尤其是尿妊娠试验及大便OB试验检测存在较多的假阳性,假阴性问题。急需一套完整胶体金试纸条检测应用的评估方案及相应的质量控制程序。本文就检验科体液组一些常见POCT项目的检测存在问题,及试纸条评估方案和质量控制管理作一简单阐述。

一种NT-proBNP(POCT)检测对早期心衰的诊断价值

目的评估一种NT-proBNP(POCT)快速免疫检测试剂早期诊断心衰的临床应用价值。方法应用深圳瑞莱公司NT-proBNP(POCT)试剂检测77例急诊疑似心衰病人血清的NT-proBNP浓度。结果 77例收集到的疑似心衰病人中,其中心衰患者24例,占31.2%,该POCT快速诊断试剂敏感度为96.0%,特异度为83.0%,阳性预测值为72.7%,阴性预测值为97.8%。ROC曲线下面值为0.793。结论瑞莱公司NT-proBNP(POCT)快速诊断试剂具有很高的阴性预测值,在心衰发病早期,是非常好的鉴别诊断非心衰患者的POCT试剂。

4种POCT血糖仪的性能评价及与全自动生化分析仪血糖检测结果的比对分析

目的本试验旨在研究临床经常使用的4种不同分析原理POCT血糖仪的性能验证评价,同时与本院生化分析仪血糖检测结果进行比对分析,评价其结果的一致性,为医院临床使用POCT血糖仪提供数据参考。方法使用4种POCT血糖仪厂家自带的2个水平的质控品进行检测并分别计算批内变异系数、批间变异系数和总变异系数,完成精密度性能评价。对4种POCT血糖仪进行卫健委临检中心POCT室间质评结果测试,完成正确度性能评价分析。对4种POCT血糖仪的血糖检测结果分别和全自动生化分析仪检测血糖的结果进行比对试验及结果分析。结果 4种POCT血糖仪的精密度及正确度结果均符合《共识》中对血糖仪精密度及正确度的要求。对4种POCT血糖仪与生化分析仪的血糖结果进行统计学差异分析,结果显示,差异均无统计学意义(P>0.05),其相关系数分别为:0.9956、0.9956、0.9946和0.9964,均大于0.98,说明相关性良好。结论 4种POCT血糖仪的性能验证符合要求,血糖仪与生化分析仪血糖测定结果基本一致。医院应合理选择并正确使用POCT血糖仪,完善的POCT质量管理体系是保证血糖检测结果准确性和可靠性的重要前提。

POCT(即时检验)在运动生化检验中的实施

简要介绍了POCT的概念、特点、技术,及在运动生化检验中的实施。

面向基层医疗卫生的POCT和数字助理的开发

论述了结合POCT与MDA应用于基层医疗卫生服务的意义、优势以及方式方法,并简单介绍了如何结合电子健康档案系统开发协同工作的POCT和MDA。