Procedia Technology最新文献

An amperometric sulfite biosensor was developed based on disposable screen printed electrodes (SPEs) and sulfite oxidase (SOx) enzyme. The developed biosensor shows good sensitivity (62 nA/ppm), reproducibility (RSD = 4%; n = 5) and a linear range of 15-1000 ppm. The applicability of the biosensor for the analysis of sodium metabisulfite in shrimp farm samples was demonstrated successfully.

A study of B-type natriuretic peptide (BNP) antigen as a good prognostic marker for patients with heart failure antigen detection employing an electrochemical immunosensor is described here. Monoclonal anti-BNP capture antibody was immobilized on streptavidin-modified SPCEs to increase the sensitivity of the assay. An anti-BNP detection antibody conjugated with horseradish peroxidase enzyme (HRP) and 3,3,5,5’-tetramethybezidine dihydrochloride (TMB) was used as a substrate, in connection with voltammetric technique was achieve by measuring the peak current. Incorporation of a streptavidin/biotin system resulted in a well-oriented antibody immobilization of the capture antibody and consequently enhanced the sensitivity of the assay. Several optimizations were performed to reduce background signals; the optimal concentration of anti-BNP detection antibody needed, the time of SPCEs were first blocked with glycine, incubated with various concentrations of BNP and HRP-conjugated anti-BNP detection antibody (0 to 100.0 ng/mL), followed by electrochemical measurement were investigated,. In conclusion, this immunosensor greatly shortened and convenient for detection of heart failure diagnosis in real serum samples.

In this work, we have investigated the modeling, design and fabrication of bio-inspired artificial muscle unit capable of contracting according to the directives sent in form of chemical messengers. This new technology has the potential to revolutionize current robotics, because it could permit a paradigm shift in robots: from electro-mechanical devices to electro-chemical devices. The bio-inspired artificial muscle will be based on basic contractile units coupled to electrochemical sensors, with the purpose of allowing adaptive and flexible control similar to that in animal locomotion. An artificial nerve termination, able to modify the chemical characteristics of the inner environment, will generate directives in form of chemical messengers. Electro-chemical sensors have been used in order to detect the presence of the chemical messengers and transform them into electronic signals to be used in conventional control electronics. This study has been focused on the development and optimization of sensing materials for inorganic ions such as hydrogen ions. Among various conducting polymers studied, polyaniline (PANI) has attracted much attention due to its unique and controllable chemical and electrical properties. PANI layer has been electrochemically deposited on the gold arrays surface by cyclic voltammetry. Preliminary experiments on PANI-modified sensors in order to obtain the better sensitivity as chemical sensing used in artificial muscle unit have been carried out. To allow diffusion of chemical messages, the system has been immersed in wet environment. Using this approach, we study the effective possibility to control, assessing the performance in terms of accuracy of the control of the contraction, the impact of the delay due to the transmission time of the chemicals, precision and stability of control.

The need for new, easy-to-use, home and decentralised diagnostics is now greater than ever and it is rapidly becoming apparent that biosensors can contribute substantially to reducing healthcare costs. New thinking is crucial to finding effective solutions that deliver the high quality of life rightly demanded by our ever ageing population while leveraging technology to deliver this in a cost-effective manner. Several key drivers are catalysing change. Personalised medicine recognises that every individual is different and needs a tailor-made health package; these differences can only be identified with an appropriate suite of diagnostics. Individuals are increasing recognising that data about their bodies should be owned by them and that they should have the choice to use and supplement this information. This generates consumer choice and drives evidence-based payment, where the success of outcomes needs to be measured. Focus on the individual and their needs drives decentralisation and the possible radical restructuring of how we deliver health management. We already see “health rooms” in pharmacies, but the next step will be health rooms in your home, in your pocket or on your wrist. These advances are underpinned by technologies facilitating mobility and data processing, but at the core are rapid, convenient and easy ways to measure our body chemistries at the genomic, proteomic and metabolomic levels. This presentation will focus on meeting these challenges using paper-based electronics, polymers and integrated electrochemical systems to deliver inexpensive instruments for a wide range of bioanalytical applications. Approaches will be illustrated by multi-parametric monitoring for the management of diabetes, chronic kidney disease and stress, reversible and label-free affinity sensors for cancer markers and heart disease, aptasensors for pathogens and cancer cells, and robust microbial-differentiation arrays. Further development will result in cost reduction and a diversity of formats such as point-of-care tests, smart packaging, telemetric strips and print-on-demand analytical devices.

We have demonstrated a chip-based diagnostics tool for the quantification of metabolites, using specific enzymes, to study enzyme kinetics and calculate the Michaelis-Menten constant. An array of 256×256 ion-sensitive field effect transistors (ISFETs) fabricated in a complementary metal oxide semiconductor (CMOS) process is used for this prototype. We have used hexokinase enzyme reaction on the ISFET CMOS chip with glucose concentration in the physiological range of 0.05 mM – 231 mM and successfully studied the enzyme kinetics of hexokinase in detail. This will promote future research towards multiplexing enzyme-based metabolite quantification on a single chip, ultimately opening a pathway towards a personal metabolome machine.

3D printing technologies will impact in a near future the biosensor community, both at the sensor prototyping level and the sensing layer organization level. The present study aimed at demonstrating the capacity of one 3D printing technique, the Digital Light Processing (DLP), to produce hydrogel sensing layers with 3D shapes unreachable using conventional molding procedures but still biosensing activity (4D printed objects).

The first model of sensing layer was composed of a sequential enzymatic reaction (glucose oxidase and peroxidase) and the generated chemiluminescent reaction in the presence of glucose and luminol used as analytical signal. Highly complex objects (fancifuball, puzzle pieces, 3D pixel, propellers, fluidic, multi-compartments) with mono-, di- and tri-components configurations were achieved and the activity of the encapsulated enzymes demonstrated.

The second model was a sandwich immunoassay protocol for the detection of Brain Natriuretic Peptide. Here, highly complex propeller shape sensing layers were produced and the recognition capability of the antibodies demonstrated.