Development of an Integrated Disposable Device for SARSCoV-2 Nucleic Acid Extraction and Detection

Objective To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods We designed,developed,and manufactured an integrated disposable device for SARS-CoV-2 nucleic acid extraction and detection.The precision of the liquid transfer and temperature control was tested.A comparison between our device and a commercial kit for SARS-Cov-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction(RT-PCR).The entire process,from SARS-CoV-2 nucleic acid extraction to amplification,was evaluated.Results The precision of the syringe transfer volume was 19.2±1.9μL(set value was 20),32.2±1.6(set value was 30),and 57.2±3.5(set value was 60).Temperature control in the amplification tube was measured at 60.0±0.0℃(set value was 60)and 95.1±0.2℃(set value was 95)respectively.SARS-Cov-2 nucleic acid extraction yield through the device was 7.10×10^(6) copies/mL,while a commercial kit yielded 2.98×10^(6) copies/mL.The mean time to complete the entire assay,from SARS-CoV-2 nucleic acid extraction to amplification detection,was 36 min and 45 s.The detection limit for SARS-CoV-2 nucleic acid was 250 copies/mL.Conclusion The integrated disposable devices may be used for SARS-CoV-2 Point-of-Care test(POCT).

一种具有识别Hg^(2+)和ClO^(-)荧光探针的设计和应用

设计合成了一种含双酯基的1,2,3-三氮唑化合物,与罗丹明B酰肼结合生成了具有“开-关”性质的荧光探针(简称L_(2)),应用光谱学表征了L_(2)的物理化学参数。L_(2)分别在DMF/Tris-HCl(1:1,v/v,pH=6.0,20μmol/L)和MeOH(20μmol/L)溶液中对Hg^(2+)和ClO^(-)显示出高选择性和灵敏性;利用荧光和紫外光谱分别测定了L_(2)对19种金属离子和14种阴离子的光学性能。实验表明,Hg^(2+)和ClO^(-)的存在使得L_(2)在585 nm和576 nm均有一个新的发射峰出现;同时伴随着荧光强度明显的增强,溶液体系发生了裸眼能识别的显色变化,表明Hg^(2+)可以将罗丹明分子的酰肼闭环结构转换为开环结构,并以1:2的比例方式生成了一种新配合物,这也被质谱、工作曲线、核磁滴定和TD-DFT计算的结果所证实;L_(2)对Hg^(2+)和ClO^(-)的检测限分别为7.45 nmol/L和0.67μmol/L。此外,生物活性测定显示L_(2)对HeLa细胞有非常低的毒性,并且可用于HeLa细胞中Hg^(2+)和ClO^(-)的细胞成像,表明L_(2)在体内可进行微测定Hg^(2+)和ClO^(-)的巨大潜力。

基于点击-去点击化学反应的Hg^(2+)荧光探针检测体系构建

基于杂化罗丹明与巯基化合物之间的点击化学反应及巯基化合物与金属汞离子的配位反应导致的去点击化学反应机理,构建香豆素杂化罗丹明探针-1,3,5-苯三硫酚-Hg^(2+)的三元荧光检测体系。在该体系中,探针能够与1,3,5-苯三硫酚中的巯基基团发生加成反应,破坏探针的共轭结构,从而导致探针的红色荧光猝灭。加入Hg^(2+)后,Hg^(2+)与1,3,5-苯三硫酚通过配位作用结合,使其从探针结构上离去,探针的共轭结构及红色荧光恢复。体系的荧光强度与Hg^(2+)在5×10^(-9)~1×10^(-8)、1×10^(-8)~1.1×10^(-7)mol/L浓度范围内呈良好的线性关系,检测限为2×10^(-9)mol/L,等倍量的常见重金属离子对Hg^(2+)的特异性识别无干扰。应用于实际饮用水样品中Hg^(2+)含量检测,回收率可达到86.7%~110.2%。

基于N掺杂Ti_(3)C_(2)MXene量子点的荧光探针用于Hg2+和S2-的传感检测

基于N掺杂Ti_(3)C_(2) MXene量子点(N-Ti_(3)C_(2) MQDs)荧光探针和配位相互作用,构建了一种检测Hg^(2+)和S^(2-)的“开-关-开”型荧光传感新方法.研究发现,制备的N-Ti_(3)C_(2) MQDs发射蓝色荧光(λem=440 nm),荧光量子产率为15.7%.Hg^(2+)与N-Ti_(3)C_(2) MQDs表面的—NH2,—COOH,—OH等官能团产生选择性配位作用,导致N-Ti_(3)C_(2) MQDs体系荧光猝灭.当加入S^(2-)后,由于S^(2-)与Hg^(2+)之间强的结合力,形成HgS沉淀,从而使N-Ti_(3)C_(2) MQDs体系荧光恢复.基于该原理,构建了一种“开-关-开”型荧光传感方法,实现了对Hg^(2+)和S^(2-)的定量检测.N-Ti_(3)C_(2) MQDs探针的荧光强度与Hg^(2+)浓度在0.02~200μmol/L范围内呈良好线性关系,检出限为10 nmol/L(S/N=3);与S^(2-)浓度在0.07~150μmol/L范围内呈良好线性关系,检出限为30 nmol/L(S/N=3).该方法具有成本低、操作简单、灵敏度高和选择性好等特点,并可用于水样中Hg^(2+)和S^(2-)的检测.

介质阻挡放电脱除NO_(x)、SO_(2)和Hg^(0)研究进展

燃煤污染物的排放为环境带来负担,减少燃煤烟气污染是控制大气环境污染的重要措施,脱硫脱硝脱汞则是烟气污染控制的重点。综述现有介质阻挡放电脱除燃煤烟气污染物研究,介绍介质阻挡放电脱除燃煤污染物机理,分析了不同结构介质阻挡放电反应器的放电原理及应用场景,主要包括空间型介质阻挡放电、沿面型介质阻挡放电、共面型介质阻挡放电、填充型介质阻挡放电和两段式介质阻挡放电;归纳了反应器反应参数、气体成分以及气体间的相互作用对脱除NO_(x)、SO_(2)和Hg^(0)的影响。讨论了催化剂协同介质阻挡放电脱除燃煤污染物与单介质阻挡放电脱除污染物的区别。确定高效率脱除NO_(x)、SO_(2)和Hg^(0)的最佳方式。随介质阻挡放电的电压和频率增加,污染物脱除效率呈增加趋势,但频率进一步增加会降低脱除效率。O_(2)在一定范围内可促进NO和Hg的氧化。微量H_(2)O在高能电子作用下产生OH^(-)和HO_(2-),从而促进SO_(2)和Hg氧化;但过量H_(2)O会抑制污染物脱除。NH3能促进NO和SO_(2)的氧化。介质阻挡放电通过激活催化剂表面产生电子和空穴,促进NO、SO_(2)和Hg^(0)的氧化,从而具有更优的污染物氧化性能。

1,3-氧硫戊环为受体的Hg^(2+)荧光探针的设计、合成及性能

Hg^(2+)是毒性最强的重金属离子之一,会造成空气、土壤和水的污染,严重损害人体健康,开发有效的分析方法检测环境体系中的Hg^(2+)尤为重要。荧光探针因其灵敏度高、选择性好、响应速度快、可实时在线检测等优点,已广泛应用于Hg^(2+)检测。以Hg^(2+)促进硫代缩醛的去保护反应设计合成了一种全新的以1,3-氧硫戊环为受体的开启型Hg^(2+)荧光探针[2-(pyren-1-yl)-1,3-oxathiolane,POX],通过^(1)H NMR、^(13)C NMR和HRMS对POX结构进行表征,考察了POX在CH_(3)CH_(2)OH/H_(2)O中对Hg^(2+)的选择性、竞争性、浓度滴定、pH滴定、时间依赖性、检出限和识别机理等。研究结果表明,POX可在较宽的pH范围内对Hg^(2+)快速识别,并表现出高度的选择性和灵敏度;向POX中加入Hg^(2+)后,在386 nm处出现明显的荧光发射峰,表明POX对Hg^(2+)呈现出显著的荧光“开启”效应,其识别过程几乎不受其他金属离子干扰;荧光滴定实验表明POX在Hg^(2+)浓度为0~6.5μmol·L^(-1)范围内具有良好的线性响应(R^(2)=0.9994),检出限为0.168μmol·L^(-1),在实际水样中检测Hg^(2+)的RSD小于2.92%。由于POX合成简单、原料易得且pH适用范围较广,可作为定性和定量检测环境中Hg^(2+)的潜在工具。

氨基酸基氮掺杂荧光碳点的制备及饮料中Hg^(2+)的检测

汞离子是一种高毒性的重金属污染物,人体摄入后会带来健康危害,因此控制食品中的汞离子含量非常重要。以柠檬酸为碳源,不同的氨基酸为氮源掺杂,采用一步水热法制备高性能荧光的碳点(CDs),探究不同氨基酸基氮掺杂对碳点荧光量子产率(QY)的影响,以及这些氨基酸基氮掺杂碳点对汞离子的响应。结果显示,不同氨基酸的碳链长度和官能团对CDs的QY有一定的影响。Hg^(2+)能高效猝灭以甘氨酸(Gly)为氮源掺杂的Gly-CDs的荧光,Gly-CDs具有良好的荧光稳定性,在优化的试验条件下,用于Hg^(2+)检测的线性范围为0.00~7.00μmol/L和8.00~60.00μmol/L,检出限为0.20μmol/L。据此构建的荧光探针用于检测实际饮料样品中的Hg^(2+),回收率在90.08%~107.90%。该方法简便、快速、灵敏、适用于饮料中Hg^(2+)的测定。

Hg^(2+)光热传感实验的设计与实践

以问题导向学习(PBL)设计了基于温度信号的Hg^(2+)光热传感综合教学实验。在该教学实验中,学生首先基于机械化学,采用湿法研磨策略,制备了具有高光热转换效率的CuS纳米颗粒(CuS NPs),而后基于CuS NPs与Hg^(2+)的沉淀置换反应诱导的CuS NPs分散液的光热信号变化实现了环境水样中Hg^(2+)的检测。将Hg^(2+)光热传感的科研成果融入实验教学环节,探讨本科化学实验的创新教学设计理念,实现了以科学研究思维来指导设计大学化学创新实验,有助于系统全面地培养学生发现问题及解决问题的能力,同时将有效提升学生的基础知识综合利用与实践创新能力,促进高校本科实验教学改革。

Effectiveness of Wastewater-Based Epidemiology as an Early Warning Tool to Detect SARS-CoV-2 (COVID-19)

Medical diagnostic tests to detect Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) for individuals in the United States were initially limited to people who were traveling or symptomatic to track disease incidence due to the cost of providing testing for all people in a community on a routine basis. As an alternative to randomly sampling large groups of people to track disease incidence at significant cost, wastewater-based epidemiology (WBE) is a well-established and cost-effective technique to passively measure the prevalence of disease in communities without requiring invasive testing. WBE can also be used as a forecasting tool since the virus is shed in individuals prior to developing symptoms that might otherwise prompt testing. This study applied the WBE approach to understand its effectiveness as a possible forecasting tool by monitoring the SARS-CoV-2 levels in raw wastewater sampled from sewer lift stations at a large public university campus setting including dormitories, academic buildings, and athletic facilities. The WBE analysis was conducted by sampling from building-specific lift stations and enumerating target viral copies using RT-qPCR analysis. The WBE results were compared with the 7-day rolling averages of confirmed infected individuals for the following week after the wastewater sample analysis. In most cases, changes in the WBE outcomes were followed by similar trends in the clinical data. The positive predictive value of the applied WBE approach was 86% for the following week of the sample collection. In contrast, positive correlations between the two data with Spearmen correlation (rs) ranged from 0.16 to 0.36. A stronger correlation (rs = 0.18 to 0.51) was observed when WBE results were compared with COVID-19 cases identified on the next day of the sampling events. The P value of 0.007 for Dorm A suggests high significance, while moderate significance was observed for the other dormitories (B, C, and D). The outcomes of this investigation demonstrate that WBE can be a valuable tool to track the progression of diseases like COVID-19 seven days before diagnostic cases are confirmed, allowing authorities to take necessary measures in advance and also enable authorities to decide to reopen a facility after a quarantine.

A novel nondestructive detection approach for seed cotton lint percentage using deep learning

Background The lint percentage of seed cotton is one of the most important parameters for evaluating seed cotton quality and affects its price.The traditional measuring method of lint percentage is labor-intensive and time-consuming;thus,an efficient and accurate measurement method is needed.In recent years,classification-based deep learning and computer vision have shown promise in solving various classification tasks.Results In this study,we propose a new approach for detecting the lint percentage using MobileNetV2 and transfer learning.The model is deployed on a lint percentage detection instrument,which can rapidly and accurately determine the lint percentage of seed cotton.We evaluated the performance of the proposed approach using a dataset comprising 66924 seed cotton images from different regions of China.The results of the experiments showed that the model with transfer learning achieved an average classification accuracy of 98.43%,with an average precision of 94.97%,an average recall of 95.26%,and an average F1-score of 95.20%.Furthermore,the proposed classification model achieved an average accuracy of 97.22%in calculating the lint percentage,showing no significant difference from the performance of experts(independent-sample t-test,t=0.019,P=0.860).Conclusion This study demonstrated the effectiveness of the MobileNetV2 model and transfer learning in calculating the lint percentage of seed cotton.The proposed approach is a promising alternative to traditional methods,providing a rapid and accurate solution for the industry.

Network Intrusion Traffic Detection Based on Feature Extraction

With the increasing dimensionality of network traffic,extracting effective traffic features and improving the identification accuracy of different intrusion traffic have become critical in intrusion detection systems(IDS).However,both unsupervised and semisupervised anomalous traffic detection methods suffer from the drawback of ignoring potential correlations between features,resulting in an analysis that is not an optimal set.Therefore,in order to extract more representative traffic features as well as to improve the accuracy of traffic identification,this paper proposes a feature dimensionality reduction method combining principal component analysis and Hotelling’s T^(2) and a multilayer convolutional bidirectional long short-term memory(MSC_BiLSTM)classifier model for network traffic intrusion detection.This method reduces the parameters and redundancy of the model by feature extraction and extracts the dependent features between the data by a bidirectional long short-term memory(BiLSTM)network,which fully considers the influence between the before and after features.The network traffic is first characteristically downscaled by principal component analysis(PCA),and then the downscaled principal components are used as input to Hotelling’s T^(2) to compare the differences between groups.For datasets with outliers,Hotelling’s T^(2) can help identify the groups where the outliers are located and quantitatively measure the extent of the outliers.Finally,a multilayer convolutional neural network and a BiLSTM network are used to extract the spatial and temporal features of network traffic data.The empirical consequences exhibit that the suggested approach in this manuscript attains superior outcomes in precision,recall and F1-score juxtaposed with the prevailing techniques.The results show that the intrusion detection accuracy,precision,and F1-score of the proposed MSC_BiLSTM model for the CIC-IDS 2017 dataset are 98.71%,95.97%,and 90.22%.

磁性聚氨基噻唑吸附剂脱除水体Hg^(2+)性能

聚多巴胺(PDA)辅助负载聚氨基噻唑(PAT)法制备了磁性颗粒吸附剂Fe_(3)O_(4)@SiO_(2)@PDA-PAT。对吸附剂进行了XRD、VSM、TG、SEM、XPS、EDS和Zeta电位等表征分析,考察了吸附剂对Hg^(2+)的吸附性能。结果表明,Fe_(3)O_(4)@SiO_(2)@PDA-PAT具有超顺磁性,在pH小于2时Zeta电位为正,pH大于2时Zeta电位为负。在303 K和Hg^(2+)浓度为50 mg/L模拟废水中,当pH为1.3和5.0时,Hg^(2+)的平衡吸附量分别为121.9 mg/g和153.1 mg/g。在强酸(如pH 1.3)和弱酸(如pH 5.0)环境下Fe_(3)O_(4)@SiO_(2)@PDA-PAT吸附Hg^(2+)的过程均是自发过程,且符合二级动力学模型和Langmuir等温吸附模型。强酸环境下(如pH 1.3)Fe_(3)O_(4)@SiO_(2)@PDA-PAT吸附Hg^(2+)是焓驱动的放热过程,弱酸(如pH 5.0)环境下是熵驱动的吸热过程。用2 mol/L混酸(盐酸和硝酸摩尔比为1∶1)作为解吸液可使Hg^(2+)解吸率达91%以上。在303 K、pH 1.3、Hg^(2+)浓度20 mg/L条件下,当Na^(+)、K^(+)、Mg^(2+)、Ca^(2+)、Cu^(2+)、Zn^(2+)、Ni^(2+)质量浓度为Hg^(2+)的20倍时,Fe_(3)O_(4)@SiO_(2)@PDA-PAT的Hg^(2+)平衡吸附量分别下降了33.2%、32.1%、20.6%、26.7%、21.2%、29.6%、17.8%。在模拟海水下,Hg^(2+)吸附量下降40.9%。Fe_(3)O_(4)@SiO_(2)@PDA-PAT具有较好的Hg^(2+)选择性,具有净化海水脱除重金属的应用潜力。

氮掺杂碳点的制备及其在Hg^(2+)测定中的应用研究

以柠檬酸为碳源,尿素、邻菲罗啉、氨水、硫脲、精氨酸为氮源,通过水热法合成了5种氮掺杂荧光碳点。对合成的碳点进行荧光性能表征,测定了每种碳点的最佳激发和发射波长,在最佳发射波长下,利用荧光猝灭对Hg^(2+)进行检测。结果表明,以精氨酸为氮源制备的碳点对Hg^(2+)检测具有较灵敏的响应,其线性范围为0.25~1.5μmol/L。

lncRNA MIR4435-2HG靶向miR-376a-3p调控胆管癌细胞生物学行为的机制研究

目的 探讨长链非编码RNA(lncRNA)MIR4435-2HG(MIR4435-2HG)对胆管癌细胞增殖、迁移、侵袭、凋亡的影响及其对微小RNA-376a-3p(miR-376a-3p)的调控作用。方法 qRT-PCR法检测人肝内胆管上皮细胞HIBEpic与人胆管癌细胞RBE中MIR4435-2HG、miR-376a-3p的表达。将si-NC、si-MIR4435-2HG、miR-NC、miR-376a-3p mimics、si-MIR4435-2HG联合anti-miR-NC、si-MIR4435-2HG联合anti-miR-376a-3p分别转染至RBE细胞,作为si-NC组、si-MIR4435-2HG组、miR-NC组、miR-376a-3p组、si-MIR4435-2HG+anti-miR-NC组、si-MIR4435-2HG+anti-miR-376a-3p组;采用MTT法、Transwell小室法及流式细胞仪分别检测细胞增殖、迁移、侵袭及凋亡情况;双荧光素酶报告基因实验验证MIR4435-2HG与miR-376a-3p的靶向关系。Western blot检测相关蛋白表达。结果 RBE细胞中MIR4435-2HG表达量升高(P<0.05),miR-376a-3p表达量降低(P<0.05)。与si-NC组比较,si-MIR4435-2HG组MIR4435-2HG表达、细胞活力及CyclinD1、MMP-2、MMP-9蛋白水平降低(P<0.05),迁移及侵袭细胞数减少(P<0.05),细胞凋亡率升高(P<0.05);与miR-NC组比较,miR-376a-3p组细胞活力及CyclinD1、MMP-2、MMP-9蛋白水平降低(P<0.05),迁移及侵袭细胞数减少(P<0.05),miR-376a-3p表达、细胞凋亡率升高(P<0.05)。MIR4435-2HG可靶向调控miR-376a-3p;与si-MIR4435-2HG+anti-miR-NC组比较,si-MIR4435-2HG+anti-miR-376a-3p组细胞活力及CyclinD1、MMP-2、MMP-9蛋白水平升高(P<0.05),迁移及侵袭细胞数增多(P<0.05),miR-376a-3p表达、细胞凋亡率降低(P<0.05)。结论 敲低MIR4435-2HG可通过靶向调控miR-376a-3p进而抑制RBE细胞增殖、迁移、侵袭,并诱导其凋亡。

Electrochemical synthesis of FeN_(x) doped carbon quantum dots for sensitive detection of Cu^(2+) ion

A novel strategy was developed to fabricate FeNx-doped carbon quantum dots(Fe-N-CQDs)to detect Cu^(2+) ions selectively as a fluorescence probe.The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon cloth electrode,which was coated with monoatomic ironanchored nitrogen-doped carbon(Fe-N-C).The obtained Fe-N-CQDs emitted blue fluorescence and possessed a quantum yield(QY)of 7.5%.An extremely wide linear relationship between the Cu^(2+) concentration and the fluorescence intensity was obtained in the range from 100 nmol L^(-1) to 1000 nmol L^(-1)(R^(2)=0.997),and the detection limit was calculated as 59 nmol L^(-1).Moreover,the Fe-N-CQDs demonstrated wide range pH compatibility between 2 and 13 due to the coordination between pyridine nitrogen and Fe^(3+),which dramatically reduced the affection of the protonation and deprotonation process between H^(+) and Fe-N-CQDs.It is notable that the Fe-N-CQDs exhibited a rapid response in Cu^(2+) detection,where stable quenching can be completed in 7 s.The mechanism of excellent selective detection of Cu^(2+) was revealed by energy level simulation that the LUMO level of Fe-N-CQDs(-4.37 eV)was close to the redox potential of Cu^(2+),thus facilitating the electron transport from Fe-N-CQDs to Cu^(2+).

聚丙烯腈改性及其对Hg^(2+)吸附研究

Hg^(2+)是生态环境中存在的对人体健康危害最大的重金属离子之一。吸附法是一种去除Hg^(2+)最简单高效的方法。因此设计成本低廉、吸附性能好且能循环利用的吸附剂是非常重要的。采用乳液自由基聚合技术制备聚丙烯腈,然后用三乙烯四胺对聚丙烯腈进行改性,得到改性后的聚丙烯腈。以废水中Hg^(2+)为吸附对象,考察不同的实验条件下,改性后的聚丙烯腈对Hg^(2+)的吸附性能。在pH值为6,Hg^(2+)浓度为40 mg/L,即时吸附量q_(t)达到最大;吸附30 min后吸附基本达到饱和。分别用伪一级吸附和伪二级吸附方程动力学模型对实验数据进行拟合,结果表明,用伪二级动力学方程可以更好描述吸附过程,说明三乙烯四胺改性聚丙烯腈对Hg^(2+)的吸附过程受Hg^(2+)扩散和-NH_(2)与Hg^(2+)的配位反应影响,为化学吸附。

MIR4435-2HG对胰腺癌预后和免疫浸润的评估价值

目的:探讨长链非编码RNA MIR4435-2HG在胰腺癌预后以及免疫浸润中的评估价值。方法:胰腺癌患者的基因表达谱及临床资料从TCGA数据库和GTEx数据库中获得。比较胰腺癌和正常胰腺组织中MIR4435-2HG的表达水平,使用Wilcoxon秩和检验。MIR4435-2HG表达与免疫细胞的相关性使用Spearman相关性分析,MIR4435-2HG高表达和低表达免疫浸润水平的差异使用Wilcoxon rank-sum检验。通过生存分析及Cox回归分析确定MIR4435-2HG的预后价值,并构建列线图预测胰腺癌总生存率。结果:MIR4435-2HG在胰腺癌中高表达,MIR4435-2HG高表达患者总体生存率和无病生存率劣于低表达患者(P<0.05)。多因素Cox回归分析显示N分期、病理分期、组织学分期、放射治疗、TSPAN6和Clorf112表达水平是胰腺癌患者总体生存率的独立影响因素(P<0.05)。MIR4435-2HG高表达与自然杀伤细胞、巨噬细胞、树突状细胞和Th1细胞的免疫浸润水平呈正相关。结论:MIR4435-2HG可能是一种新的胰腺癌预后生物标志物。

Highly Sensitive Poly-N-isopropylacrylamide Microgel-based Electrochemical Biosensor for the Detection of SARS-COV-2 Spike Protein

Objective Late 2019 witnessed the outbreak and widespread transmission of coronavirus disease 2019(COVID-19),a new,highly contagious disease caused by novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Consequently,considerable attention has been paid to the development of new diagnostic tools for the early detection of SARS-CoV-2.Methods In this study,a new poly-N-isopropylacrylamide microgel-based electrochemical sensor was explored to detect the SARS-CoV-2 spike protein(S protein)in human saliva.The microgel was composed of a copolymer of N-isopropylacrylamide and acrylic acid,and gold nanoparticles were encapsulated within the microgel through facile and economical fabrication.The electrochemical performance of the sensor was evaluated through differential pulse voltammetry.Results Under optimal experimental conditions,the linear range of the sensor was 10-13-10-9 mg/m L,whereas the detection limit was 9.55 fg/mL.Furthermore,the S protein was instilled in artificial saliva as the infected human saliva model,and the sensing platform showed satisfactory detection capability.Conclusion The sensing platform exhibited excellent specificity and sensitivity in detecting spike protein,indicating its potential application for the time-saving and inexpensive detection of SARS-CoV-2.

Clinical application of SARS-CoV-2 antibody detection and monoclonal antibody therapies against COVID-19

The purpose of this study was to investigate the clinical application of severe acute respiratory distress syndrome coronavirus-2(SARS-CoV-2)specific antibody detection and anti-SARS-CoV-2 specific monoclonal antibodies(mAbs)in the treatment of coronavirus infectious disease 2019(COVID-19).The dynamic changes of SARS-CoV-2 specific antibodies during COVID-19 were studied.Immunoglobulin M(IgM)appeared earlier and lasted for a short time,while immunoglobulin G(IgG)appeared later and lasted longer.IgM tests can be used for early diagnosis of COVID-19,and IgG tests can be used for late diagnosis of COVID-19 and identification of asymptomatic infected persons.The combination of antibody testing and nucleic acid testing,which complement each other,can improve the diagnosis rate of COVID-19.Monoclonal anti-SARS-CoV-2 specific antibodies can be used to treat hospitalized severe and critically ill patients and non-hospitalized mild to moderate COVID-19 patients.COVID-19 convalescent plasma,highly concentrated immunoglobulin,and anti-SARS-CoV-2 specific mAbs are examples of anti-SARS-CoV-2 antibody products.Due to the continuous emergence of mutated strains of the novel coronavirus,especially omicron,its immune escape ability and infectivity are enhanced,making the effects of authorized products reduced or invalid.Therefore,the optimal application of anti-SARS-CoV-2 antibody products(especially anti-SARS-CoV-2 specific mAbs)is more effective in the treatment of COVID-19 and more conducive to patient recovery.

Rhodamine 6G-based Chemosensor for the Visual Detection of Cu2＋ and Fluorescent Detection of Hg2＋ in Water

A novel water soluble chemosensor 1 based on rhodamine 6G spirolactam scaffold has been synthesized and characterized.Upon addition of a wide range of the environmentally and biologically relevant metal ions,chemosensor 1 shows a colorimetric selective Cu2＋ recognition from colorless to pink confirmed by UV-Vis absorption spectral changes,while it also exhibits a fluorometric selective Hg2＋ recognition by fluorescence spectrometry.An absorption enhancement factor over 17-fold with 1-Cu2＋ complex and a fluorescent enhancement factor over 45-fold with 1-Hg2＋ complex were observed.Their recognition mechanisms were assumed to be a 1：1 stoichiometry for 1-Cu2＋ complex and a 1：2 stoichiometry for 1-Hg2＋ complex,respectively,which were proposed to be different ligation leading to the ring-opening of rhodarnine 6G spirolactam.Furthermore,the detection limits for CU2＋ or Hg2＋ were 3.3 × 10-8 or 1.7x 10-7 mol/L,respectively.