New Solution of Substrate Concentration in the Biosensor Response by Discrete Homotopy Analysis Method

In this article, Discrete Homotopy Analysis Method (DHAM), as a new numerical method, is employed to investigate amperometric biosensor at mixed enzyme kinetics and diffusion limitation. Mathematical modeling of the problem is developed utilizing non-Michaelis-Menten kinetics of the enzymatic reaction. Different results are obtained for different values of the dimensionless parameters described in the paper. The presented solution is then compared with the available actual and simulated results.

DESIGN OF MICROPHYSIOMETER BASED ON MULTIPARAMETER CELL-BASED BIOSENSORS FOR QUICK DRUG ANALYSIS

Cellular metabolism arouses the changes of substance in extracellular physiological microenvironment,and the metabolic level reflects the physiological state of cells.This paper developed a novel microphysiometer automatic analysis instrument based on multiparameter cell-based biosensors for quick drug analysis.This study included the multiparameter cell-based biosensors,cell culture chamber,drug auto-injection detection and analysis.The analysis instrument was capable of real-time detection for the acidic product and other chemical parameters generated by the cellular metabolism in the micro-volume.Finally,the paper employs human breast cancer cell line MCF-7 and drug experiments to verify the performance of microphysiometer,and study effects of different drugs on cell metabolism.Further,the research explores drug analysis method of the multiparameter microphysiometer.The results showed that the cell-based microphysiometer system provides a utility platform for rapid,long-term and automatic cell physiological environment detection and drug analysis.

A novel thermal biosensor based on enzyme reaction for pesticides measurement

A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical reference column, which is set for eliminating the unspecific heat. The enzyme reaction takes place in the enzyme reaction column at a constant temperature(40℃) realized by a thermoelectric thermostat. Thermosensor based on the thermoelectric module containing 127 serial BiTe-thermocouples is used to monitor the temperature difference between two effluents from enzyme reaction column and reference column. The ability of this biosensor to detect pesticides is demonstrated by the decreased degree of the hydrolytic heat in two types of thermosensor mode. The hydrolytic reaction is inhibited by 36% at 1 mg/L DDVP and 50 % at 10 mg/L DDVP when cell-typed thermosensor is used. The percent inhibition is 30% at 1 mg/L DDVP and 42% at 10 mg/L DDVP in tube-typed thermosensor mode. The detection for real sample shows that this biosensor can be used for detection of organophosphate pesticides residue.

Optimization on Production Key Factors of Microbial Fermented Feed and Analysis on Composition Variation During Fermentation

[ Objective] In order to study the production key factors of microbial fermented feed and the composition variation during fermentation. [ Methods ] Water, temperature, energy and protein were selected to study the effects on microbial fermented feed. And the fermentation conditions were optimized. Changes on nutrient composition during fermentation were determined and analyzed. [ Result ] Test results showed that feed formula with high sugar content, low protein, 34% - 36% water content, high fermentation temperature was more conducive to the production and actual production needs of fermentation strains. During the fermentation, strains showed interactions, test tended to be completed at the 144^th h after the fermentation, and number of lactic acid bacteria reached the peak of 1.86×10^9 strain/g, contents of lactic acid could even reach 0.89%. As time prolonged, contents of total energy, fiber and isothiocyanate gradually reduced, while contents of water and protein increased slightly. Contents of vitamin were stable, which in an order of VB〉 VE 〉 Vx 〉 VA 〉 VD. Composition of amino acids showed an better change, contents of glutamic acid and proline decreased slowly, while contents of glycine and phenylalanine increased slowly. [ Conclusion] High quality microbial fermentation feed could improve the palatability and safety of feed and keep the intestinal balance of livestock and poultry, which had broad application prospect.

Degradation of Microbes for the Crude Oil Contaminants

Production and storage-transportation of crude oil can not only give rise to soil pollution but also destroy ecological environment. Degradation of microbes for oily soil was studied with the instnunent, Geofina Hydrocarbon Meter (GHM), by experimental analysis qualitatively and quantitatively in the paper. Analytical result showed that the crude oil could be considerably degraded by eating-oil microbes in oily soil and the number of eating-oil microbes increased while the working hours of oil-well risi...

Wearable sweat biosensors on textiles for health monitoring

With the rapid technological innovation in materials engineering and device integration,a wide variety of textilebased wearable biosensors have emerged as promising platforms for personalized healthcare,exercise monitoring,and pre-diagnostics.This paper reviews the recent progress in sweat biosensors and sensing systems integrated into textiles for wearable body status monitoring.The mechanisms of biosensors that are commonly adopted for biomarkers analysis are first introduced.The classification,fabrication methods,and applications of textile conductors in different configurations and dimensions are then summarized.Afterward,innovative strategies to achieve efficient sweat collection with textile-based sensing patches are presented,followed by an in-depth discussion on nanoengineering and system integration approaches for the enhancement of sensing performance.Finally,the challenges of textile-based sweat sensing devices associated with the device reusability,washability,stability,and fabrication reproducibility are discussed from the perspective of their practical applications in wearable healthcare.

Environmental Analysis with 2D Transition-Metal Dichalcogenide-Based Field-Effect Transistors

Field-effect transistors(FETs)present highly sensitive,rapid,and in situ detection capability in chemical and biological analysis.Recently,two-dimensional(2D)transition-metal dichalcogenides(TMDCs)attract significant attention as FET channel due to their unique structures and outstanding properties.With the booming of studies on TMDC FETs,we aim to give a timely review on TMDCbased FET sensors for environmental analysis in different media.First,theoretical basics on TMDC and FET sensor are introduced.Then,recent advances of TMDC FET sensor for pollutant detection in gaseous and aqueous media are,respectively,discussed.At last,future perspectives and challenges in practical application and commercialization are given for TMDC FET sensors.This article provides an overview on TMDC sensors for a wide variety of analytes with an emphasize on the increasing demand of advanced sensing technologies in environmental analysis.

Analytical Solution of Substrate Concentration in the Biosensor Response

Homotopy analysis method (HAM) is employed to investigate amperometric biosensor at mixed enzyme kinetics and diffusion limitation. Mathematical modeling of the problem is developed utilizing non-Michaelis-Menten kinetics of the enzymatic reaction. Different results of the problem are obtained for different values of the dimensionless parameters. Accuracy of the obtained results is verified by comparing them with the available actual and simulated ones. It is concluded that the obtained solution can be considered as a promising one to investigate different aspects of the phenomena.

Analytical expressions of steady-state concentrations of species in potentiometric and amperometric biosensor

A mathematical model of potentiometric and amperometric enzyme electrodes is discussed. The model is based on the system of non-linear steady-state coupled reaction diffusion equations for Michaelis-Menten formalism that describe the concentrations of substrate and product within the enzymatic layer. Analytical expressions for the concentration of substrate, product and corresponding flux response have been derived for all values of parameters using Homotopy analysis method. The obtained solution allow a full characterization of the response curves for only two kinetic parameters (The Michaelis constant and the ratio of overall reaction and the diffusion rates). A simple relation between the concentration of substrate and products for all values of parameter is also reported. All the analytical results are compared with simulation results (Scilab/Matlab program). The simulated results are agreed with the appropriate theories. The obtained theoretical results are valid for the whole solution domain.

Molecular cloning and expression analysis of Crustin-like gene from Chinese shrimp Fenneropenaeus chinensis

A new member of antimicrobial protein genes of the Crustin family was cloned from haemocytes of the Chinese shrimp Fennero- penaeus chinensis by 3 ′and 5′ RACE. The full-length cDNA of Crustin-like gene contains a 390 bp open reading frame, encoding 130 amino acids. The deduced peptide contains a putative signal peptide of 17 amino acids and mature peptide of 113 amino acids. The molecular mass of the deduced mature peptide is 12. 3 ku. It is highly cationic with a theoretical isoelectric point of 8.5. The deduced amino acids sequence of this Crustin showed high homology with those of Penaeus （ Litopenaeus ） setferus. Northern blotting showed that the cloned Crustin gene was mainly expressed in haemocytes, gill, intestine, and RNA in situ hybridization indicated that the Crustin gene was constitutively expressed exclusively in haemocytes of these tissues. Capillary elec- trophoresis RT-PCR analysis showed that Crustin was up-regulated dramatically from 12 to 48 h after a brief decrease of mRNA during first 6 h in response to microbe infection. The level of Crustin mRNA began to restore at 72 h post-challenge. This indicated that Crustin gene might play an important role when shrimps are infected by bacterial pathogen.

Design optimization of highly sensitive LSPR enhanced surface plasmon resonance biosensors with nanoholes

For breaking through the sensitivity limitation of conventional surface plasmon resonance （SPR） biosensors, novel highly sensitive SPR biosensors with Au nanopartieles and nanogratings enhancement have been proposed recently. But in practice, these structures have obvious disadvantages. In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parame- ters on the performance is investigated by using rigorous coupled wave analysis （RCWA）. Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters. The results indicate that significant sensitivity increase is associated with localized surface plasmons （LSPs） excitation mediated by nanoholes. Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves＇ width are obtained simultaneously under optimized structural parameters.

Recent Advances in Visual Electrochemiluminescence Analysis

Due to the advantages of low background interference and high sensitivity, electrochemiluminescence (ECL)-based sensor has developed rapidly in recent years. The ECL sensors have shown the potential in the ultrasensitive and real-time analysis. Especially, the visual ECL analysis, including visual detection, cell imaging and single particle analysis, has offered many unique sensing platforms for analysis research and point-of-care testing. The high throughput ECL image analysis can not only provide ECL intensity but also reveal more information about the chemical reaction activity of particle and the physi-ological processes of cell operation. Therefore, we review the novel ECL luminophore, sensing systems, and successful applications in the visual ECL detection and imaging in this paper. First, the different ECL luminophore is summarized. Second, we discuss the ECL sensing mechanisms, focusing on the advantages and limitations of different sensing methods. Then, we highlight the recent advances in representative examples of visual ECL analysis, including aptasensing, multiplex immunoassays, cell imaging and single-particle analysis. At last, the outlook and prospects for the future visual ECL analysis are discussed based on the current development of ECL research.

Cell-based biosensors:Towards the development of cellular monitoring

Cell-based biosensors (CBBs), a research hot-spot of biosensors, which treat living cells as sensing elements, can detect the functional information of biologically active analytes. They characterize with high sensitivity, excellent selectivity and rapid response, and have been applied in many fields, such as biomedicine, environmental monitoring and pharmaceutical screening. Recently cell-cultured technology, silicon microfabrication technology and genetic technology have promoted exploration of CBBs dramatically. To elucidate the novel research findings and applications of cell- based biosensors, this paper summarizes various research approaches, presents some challenges and proposes the research trends.

A functional approach toward xerogel immobilization for encapsulation biocompatibility of Rhizobium toward biosensor

Sol-gel derived silica has tremendous applications as a biocompatible scaffold for the immobilization of cells. The use of xerogel as a matrix in the blueprint of biosensors is an appealing proposition due to several inimitable characteristics of xerogels, primarily because of their high porous nature, amendable pore size, and exceptionally large internal surface area. Morphological （X-Ray Diffraction and Thermogravimmetric Analysis） and optical （Fourier Transform Infrared and UV-Vis absorption） studies of the silica matrices with entrapped Rhizobial （Rz） structure of the biomaterial has been made. Temporal and concentration dependent studies were conducted for impregnated samples; it showed that the response time for the new biosensor for determining the concentration of Rz is less than 20 min. In this work, first time a novel avenue to create a generic approach for the fabrication of biosensor has been created.

Sustainability evaluation for a circular maize-pig system driven by indigenous microbes:a case study in Northeast China

Sustainable agricultural development is a topic of global concern aiming at satisfying food demand of the growing population while reducing impact on environment.Circular agriculture has become a promising development pattern with the advantages of complementing environmental resources,replacing feedback from outside system,and processing waste of bottom of system,etc.This study combined economic analysis,life cycle assessment and emergy accounting to evaluate sustainability of an integrated maize-pig system(IS)driven by indigenous microbes in Northeast China,compared with separated maize and pig system(SS).IS reduced input of concentrate feed,coal,vaccines,disinfectants,fertilizer and labor by 14.35%,100%,46.11%,100%,60.1%and 60.8%driven by indigenous microbes.Economic analysis results showed that IS has 82.88%higher profit than that of SS.The sum of potential environmental impacts of IS was lower than SS for 80.65%according to lifecycle assessment.The emergy results revealed that IS performed better sustainability.Internal feedback emergy for fertilizer and local resources for maize straw increasing of IS significantly improved emergy efficiency.The reduction resulted in nonrenewable resources decreased 33.01%than that of SS,and increased renewable resources by 67.81%,which reduced environmental load ratio of IS by 60.08%of IS.Meanwhile,these factors were the primary factors generating higher sustainability of IS.Overall,the integrated maize-pig system driven by indigenous microbes in this study can effectively alleviate the problems caused by agricultural waste and promote sustainable agricultural development.

Identification and development of a glucaric acid biosensor in Saccharomyces cerevisiae

Metabolic biosensors are increasingly used in metabolic engineering and synthetic biology.In this study,using Saccha-romyces cerevisiae as a model system,we developed a methodology to identify promoter elements that are responsive to glucaric acid.Through transcriptome analysis,it was found that multiple genes were upregulated when cells were exposed to high concentrations of glucaric acid.From the promoters of these candidate genes,the YCR012W promoter(PYCR012W)was observed to specifically respond to glucaric acid in a dose-dependent manner.To gain further insight into the binding site of glucaric acid-responsive activators,we truncated the promoter and revealed that the-564 to-464 bp regions of PYCR012W was essential for glucaric acid-responsive expression.To investigate the glucaric acid-responsive transcription factors,we predicted the transcription factor binding sites in the-564 to-464 bp region of PYCR012W and found that two transcription factors,Ash1p and Cbf1p,might be linked to glucaric acid responses.The strategies used in this study outline a method for the identification and development of metabolic biosensors.

Analysis of Transcriptome Changes Induced by Ptr ToxA in Wheat Provides Insights into the Mechanisms of Plant Susceptibility

To obtain greater insight into the molecular events underlying plant disease susceptibility, we studied transcriptome changes induced by a host-selective toxin of Pyrenophora tritici-repentis, Ptr ToxA （ToxA）, on its host plant, wheat. Transcriptional profiling of ToxA-treated leaves of a ToxA-sensitive wheat cultivar was performed using the GeneChip Wheat Genome Array. An improved and up-to-date annotation of the wheat microarray was generated and a new tool for array data analysis （BRAT） was developed, and both are available for public use via a web-based interface. Our data indicate that massive transcriptional reprogramming occurs due to ToxA treatment, including cellular responses typically associated with defense. In addition, this study supports previous results indicating that ToxA-induced cell death is triggered by impairment of the photosynthetic machinery and accumulation of reactive oxygen species. Based on results of this study, we propose that ToxA acts as both an elicitor and a virulence factor.

电致化学发光传感技术的种类及在食品分析中的研究进展

电致化学发光传感技术(Electrochemiluminescence,ECL)是一种结合了电化学和光化学的分析方法,因其可控性强、灵敏度高和响应速度快等优势在食品分析领域引起了广泛关注。ECL是通过改变发射物或共反应物的浓度,使其信号强度发生变化,从而实现对目标物质的灵敏检测。首先,该文总结了经典ECL检测体系及基于新型发射物和共反应物的检测体系,并重点介绍了新型发射物中金属纳米团簇和量子点的最新进展,举例阐述其ECL传感器的结构和检测原理。其次,综述了ECL传感器在食品分析领域中的研究进展。最后对ECL传感技术的未来发展趋势进行了展望,为食品中营养成分和污染物的检测提供参考,同时也促进该技术的进一步研究,助力未来食品检测发展。

某院2019至2021年PIVAS沉降菌检测结果分析

目的分析医院静脉用药调配中心(PIVAS)洁净区沉降菌检测结果,评估洁净区的洁净程度。保证洁净区环境指标达标,便于进行精细化管理。方法统计2019至2021年PIVAS内部不同洁净级别区域沉降菌检测结果,并对检测数据进行对比分析处理。结果操作台3年合格率频数大部分集中在>90%,调配间3年合格率均>90%;操作台合格率两两比较显示合格率呈逐年增高趋势,差异均有统计学意义(P<0.05);操作台检测结果与月份无明显关系(P>0.05)。结论沉降菌检测结果影响因素较复杂,只有按要求规范严格做好各方面工作才能保证检测结果的真实,才能准确评估洁净区的洁净程度。

基于纳米酶生物传感器检测真菌毒素的研究进展

纳米酶作为一种具有天然模拟酶活性的纳米材料,因兼具纳米材料性能与类似天然酶的良好催化性能,已被广泛应用于新型真菌毒素生物传感器的研发。该文对纳米酶生物传感器检测原理进行了简单介绍,并根据真菌毒素检测机理进行分类,综述了近年比色、荧光和电化学纳米酶生物传感器在真菌毒素检测方面的研究进展,讨论并比较了上述3类纳米酶生物传感器在真菌毒素检测中的优势。最后,针对目前存在的问题和发展前景进行了展望。