Procedia Technology最新文献

Simple and inexpensive strategies to enhance the electrochemical properties of carbon and gold-sputtered Paper-Working-Electrodes (PWE) disks were developed through gold nanoparticles (AuNPs)electrogenerated from AuCl₄⁻ solutions by chronopotentiometry or cyclic voltammetry. In order to ensure a good connection, the wax-defined paper area was adhered to the working electrode of a conventional screen-printed electrode (SPCE) that allows the use of the reference and auxiliary electrodes. Nanostructured paper-based electrodes were characterized by Scanning Electron Microscopy (SEM). Possibilities of use for As(III) determination in wines were also evaluated.

The use of ICT in the health care system is aimed to increase efficacy and decrease costs. We have designed a system and services for mobile monitoring of vital physiological parameters and environmental context. The system is based on a small multi-functional wireless body sensor for simultaneous measurement of ECG, temperature, heart rate, respiration rate, and movement. The sensor is wirelessly connected through Bluetooth Smart to a Smartphone. When necessary, the measurements are transferred to a server and can be accessed by authorized personnel. The contribution of the system to improved quality and efficiency of medical care is validated and estimated through several pilot studies.

Seafood, especially red fish is rich in histidine, which is essential for infants and adults. With fish freshness decline or spoilage, enzyme catalysis or microorganisms cause decarbonylation of histidine to form histamine, which threatens human body by dietary and affects allergic and inflammatory reaction. Current histamine assay needs complex operation, numerous steps, and time-consuming. In this study, a functionalized nanoporous alumina membrane was used to construct a rapid and highly sensitive impedance biosensor with magnetic nanoparticles (MNPs) for target molecule pre-concentration and separation. When the functionalized MNPs accumulated histamine, they were separated by magnetism from samples and added to the anti-histamine antibody modified nanoporous alumina membrane causing blocking effect in the nanopores by immune reaction. Impedance increased as histamine concentrations increased from 1 μM to 40 mM. The limit of detection was as low as several micromolar. The biosensor provides a novel, highly sensitive and specific sensing mechanism and constructs a new technology and method for justifying seafood freshness to prevent toxic reaction in human body. It is a new approach for food quality safety control.

Quantification of biomarkers closest to the patient remains an impressive challenge for the development of personalized medicine. The detection of D-dimer, a fibrin degradation product, indicative of deep vein thrombosis, pulmonary embolism or stroke is a particular biomarker of interest. In this study, we developed a quantitative assay based on the measurement of autologous red blood cells agglutination by a lens-free device. An indicator, obtained from the shape of the gray level histogram of the images, allows us for a linear quantification of D-dimer opening the door for a Point-of-Care device.

The main idea of this project is to utilise microorganisms (bacteria) as sensing elements in the inhibition type biosensors for detection of heavy metals and pesticides which are dissolved in water. This work focuses on developing novel, cost-effective sensing technologies for detection of environmental pollutions. Two types of bacteria (E. coli and S. oneidensis) which are inhibited by heavy metals were used in this work. The bacteria density or concentration was characterised first with optical techniques of fluorescence microscopy, optical density OD600, and flow cytometry. Then a series of electrochemical measurements were carried out on the same bacteria samples. The study of the effect of heavy metals on the above bacteria revealed a possibility of pattern recognition of the above pollutants.

Surface acoustic wave (SAW) devices are well-known for gravimetric sensor applications. In biosensing applications, chemical- and biochemically evoked adsorption processes at surfaces are detected in liquid environments using delay-line or resonator sensor configurations, preferably in combination with appropriate microfluidic devices. In this paper, a novel SAW-based impedance sensor type is introduced which uses only one interdigital electrode transducer (IDT) simultaneously as SAW generator and sensor element. It is shown that the amplitude of the reflected S₁₁ signal directly depends on the input impedance of the SAW device. The input impedance is strongly influenced by mass adsorption which causes a characteristic and measurable impedance mismatch.

Okadaic acid (OA) is a representative diarrhetic shellfish poisoning toxin which is highly toxic and carcinogenic to human, and rich in polluted shellfish. In this work, a novel and high sensitive fluorescence immunosensor based on magnetic beads (MBs) and quantum dots (QDs) had been developed for OA detection. Carboxylic acid modified MBs were used as supporter to immobilize the OA-BSA, competed with the OA in the sample solution to bind with the anti-OA monoclonal antibody (OA-MAb). The CdTe QDs (EX600 nm) labeled IgG was served as secondary antibody to perform fluorescence detection. A portable flow cytometry, Moxi Flow was applied for OA on-site quantification. The results showed that the OA concentration was inversely proportional to the QDs fluorescence intensity. The limit of detection (LOD) was 0.05 μg/L with a linear range of 0.2–20 μg/L for OA detection, which was far lower than traditional id-ELISA strategy. Moreover, OA detection for the real sample could be completed within 1 hour. The matrix effect and the recovery rate were also assessed during real sample measurement, showing a high recovery.

Prostate carcinoma is the most common leading cause of cancer-related deaths in men, aside from lung cancer. To date, proteolytically-active prostate specific antigen (PSA) serine protease is a useful diagnostic serological marker for the early diagnosis and monitoring of prostate cancer. In the past years, researchers executed a lot of research to increase the utility and applicability of PSA detection methods. However, these methods were usually frustrated by limitation in sensitivity, specificity, times constrains and ease of on-site application. Thus, there is a need for novel direct and highly sensitive PSA detection methods. This work showed the ability of the developed electrochemical and optical (Surface Plasmin Resonance (SPR) and colorimetric) biosensors to detect PSA with high sensitivity and specificity and within a short timing. Moreover, these novel approaches can be implemented in other miniaturized configurations such as screen printed electrode and paper-based low-cost point-of-care biosensor due to the elimination of washing and blocking steps as well as the amplification and labelling procedure.