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.

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.

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.

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.

DropLab:an automated magnetic digital microfluidic platform for sample-to-answer point-of-care testing—development and application to quantitative immunodiagnostics

In point-of-care testing(POCT),tests are performed near patients and results are given rapidly for timely clinical decisions.Immunodiagnostic assays are one of the most important analyses for detecting and quantifying protein-based biomarkers.However,existing POCT immunodiagnostics mainly rely on the lateral flow assay(LFA),which has limited sensitivity or quantification capability.Although other immunodiagnostic assays,such as enzyme-linked immunosorbent assays(ELISAs),offer more sensitive and quantitative results,they require complex liquid manipulations that are difficult to implement in POCT settings by conventional means.Here,we show the development of DropLab,an automated sample-in-answer-out POCT immunodiagnostic platform based on magnetic digital microfluidic(MDM)technology.DropLab performs microbead-based ELISA in droplets to offer more sensitive and quantitative testing results.The intricate liquid manipulations required for ELISA are accomplished by controlling droplets with magnetic microbeads using MDM technology,which enables us to achieve full automation and easy operations with DropLab.Four ELISAs(the sample in triplicates and a negative control)can be run in parallel on the thermoformed disposable chip,which greatly improves the throughput and accuracy compared to those of other POCT immunodiagnostic devices.DropLab was validated by measuring two protein targets and one antibody target.The testing results showed that the limit of detection(LOD)of DropLab matched that of the conventional ELISA in a microwell plate.DropLab brings MDM one step closer to being a viable medical technology that is ready for real-world POCT applications.

POCT技术在军事和突发事件医学救援中的应用现状与思考

现场快速检验技术(point of care testing,POCT)因具有快(报告结果快)、边(患者身边)、便(操作简便)和易(读取结果容易)等优势,广泛应用于军事行动及战备、事故灾难、反恐等突发事件的救援现场。主要对POCT技术在军事和突发事件医学救援检验方法学、检验项目和检验模块装备等方面的应用进行阐述,并对POCT技术在应用中需改进的问题以及该技术在未来发展方向上应该侧重提高的方面进行了讨论和分析。

Point-of-care testing for lysine concentration in swine serum via blue-emissive carbon dot-entrapped microfluidic chip

Lysine is one of the essential amino acids and plays a vital role in the growth,development and health of pigs.Blood lysine concentration is a direct indication of lysine status;however,current methods can not satisfy the demands for rapid and on-site lysine concentration measurement of swine serum.Here,we developed blue-emissive nitrogen-doped carbon dots as a fluorescence probe for the determination of lysine with high fluorescence quantum yield,stability,sensitivity and specificity.The carbon dots were entrapped within hydrogel microstructures to fabricate microfluidic chips for rapid assay for lysine quantification.We further developed an imaging attachment to integrate the microfluidic chip and a smartphone into a portable point-of-care testing platform.This platform requires only 3μL sample and has a linear detection range of 25 to 300μmol/L with a limit of detection less than 16μmol/L,which covers the normal range of lysine concentration in swine serum.We tested lysine concentration in swine serum using this platform with high accuracy,low sample consumption,and within 3 min.Together,these results may provide a rapid and portable platform for dynamic monitoring of swine lysine status and contribute to precise feed formula modulation with low-protein diet strategy.

基于POCT的医院血糖信息化管理实践与效果分析

目的 探索基于即时检验技术的全院联动血糖信息化系统对患者血糖进行管理。方法 应用即时检验技术,实现患者床旁血糖即时检测,构建患者异常血糖管理体系,实现血糖危急值闭环管理。结果 2022年1月至10月期间测量血糖57497人,其中达标人数48528人,达标率84.80%。共测量1236398次,其中达标次数407517次,达标率32.96%。2022年1月至10月期间,低血糖共出现24237次,占比1.96%;异常低值共出现13333次,占比1.08%;危急低值共出现2536次,占比0.21%;异常高值共出现804644次,占比65.08%;危急高值共出现87166次,共占比7.05%。结论 基于即时检验技术的院内血糖信息化管理可简化医护人员劳动,提高工作效率,减少医疗差错,同时可对患者血糖进行全面专业管理,提高血糖危急值管理水平。

新型检测技术在即时检测(POCT)中的应用

即时检验(point-of-care testing,POCT),又称现场快检或床旁快检,是一种可以在现场及时完成检测并报告结果的检测方式。然而,传统POCT难以充分满足精准定量与自动化检测等需求,精准诊疗时代急切需要更准、更快、更便利、更普惠的新型POCT产品。随着生物学、化学、电子信息学、工业加工等学科的技术革新和进步,层出不穷的创新型POCT诊断技术在临床诊疗、公共卫生防控及大健康管理中展现出了极具优势的应用价值和广阔的应用前景。本综述旨在对POCT发展、新技术进行系统性概述,对传统检测技术与新型检测技术在POCT中应用进行讨论和前景展望。

即时检测仪器与电化学发光仪检测心脏标志物的对比研究

目的:对比分析两种即时检测(POCT)仪器与Roche电化学发光仪检测心脏标志物的相关关系,为临床检验选择POCT仪器提供参考。方法:选取2020年11月在中国中医科学院西苑医院就诊的20例患者血液样本,其浓度范围覆盖检测结果可报告范围,使用两种POCT仪器(分别命名为仪器A和仪器B)检测血浆肌红蛋白(Myo)、肌酸激酶同工酶质量(CKMB mass)、心肌钙蛋白I(cTnI)、氨基末端脑钠肽前体(NT-proBNP)/B型钠尿肽(BNP)的浓度水平,以电化学分析仪检测结果为参考,分别采用pearson相关分析和Kappa检验评价两种POCT仪器与Roche电化学发光仪检测结果的相关性和一致性。结果:仪器A和仪器B检测结果与Roche电化学发光仪检测Myo、CK-MB mass、cTnI、NT-proBNP/BNP结果均有较好的相关性(r_(仪器A)=O.994、0.989、0.917、0.996,r_(仪器B)=0.928、0.934、0.883、0.977,P<0.05)。在一致性比较中,仪器A检测Myo、CK-MB mass、cTnI、NT-proBNP与电化学分析仪的符合率分别为90%、100%、70%和100%;仪器B检测结果的符合率分别为90%、95%、70%和100%,两种POCT仪器与Roche电化学发光仪均具有较好的一致性(Kappa_(仪器A)=0.798、1.00、0.429、1.00,Kappa_(仪器B)=0.794、0.886、0.429、1.00)。两种仪器的精密度均<10%。结论:两种POCT仪器均能满足临床检测要求,在检测心脏标志物时与电化学发光仪有较好的相关性。

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。

神奇“魔法条”之新冠病毒的快速检测

胶体金作为商业化的即时检验POCT(point-of-care test)免疫层析技术中最广泛的标记物之一,具有显著的颜色特征,后期无需可视化改造,且形态稳定、环境友好。本文试纸条制作过程简单,不需要大型贵重仪器。采用柠檬酸三钠还原氯金酸制备胶体金,将胶体金标记在新冠病毒的核衣壳N蛋白抗体上,通过在免疫层析试纸条可视区形成类似三明治结构的抗体-抗原-抗体夹心复合物,并以此复合物的红色检测线作为新冠病毒的定性分析依据。该检测方法裸眼可测、操作简单、且快速(10 min)、灵敏(检测限为0.5 ng∙mL^(−1))、低成本(每条不超过5元)。实验过程可以引导学生体验生命体系中抗原抗体相互作用引发的特异性生命化学反应,激发学生对化学、生物、生命科学和纳米材料等学科相互融合的可视化快检技术的浓厚研究兴趣。

基于微流控芯片的新型冠状病毒检测研究进展

微流控芯片是集成化、高通量、低成本、便携式的生物分析检测工具,近年来在新型冠状病毒(SARS-CoV-2)检测中备受关注。本文综述了微流控芯片及其系统在SARS-CoV-2检测中的最新进展,介绍并对比了微流控芯片的制备材料和成型工艺,着重阐述了基于微流控芯片的核酸分子检测、血清学检测和即时检测(POCT)技术的应用研究进展,为检测方法的创新设计和芯片制备提供参考。将现有生物检测技术与微流控设备有效结合,可以实现SARS-CoV-2的高效、灵敏和准确检测,基于微流控芯片的病毒检测方法呈现出多样化、集成化的特点,是传统病毒检测方法的有效替代方案。本文探讨了各种检测技术的适用性和现有挑战,将帮助学者开展更为广泛深入的生物医学分析检测研究,深化认识先进检测技术与微流控技术的发展前景。