Biosensor

This work was supported by the project "Biosensoristica innovativa per i test sierologici e molecolari e nuovi dispositivi PoCT per la diagnosi di infezione da SARS-CoV-2" funded in 2020 by "Bando Straordinario di Ateneo per Progetti di Ricerca Biomedica in Ambito SARS-COV-2 e COVID-19"-University of Parma ABSTRACT Recent advances in Internet-of-Things technology have opened the doors to new scenarios for biosensor applications. Flexibility, portability, and remote control and access are of utmost importance to move these devices to people's homes or in a Point-of-Care context and rapidly share the results with users and their physicians. In this paper, an innovative portable device for both quantitative and semi-quantitative electrochemical analysis is presented. This device can operate autonomously without the need of relying on other devices (e.g., PC, tablets, or smartphones) thanks to built-in Wi-Fi connectivity. The developed hardware is integrated into...

Recently, a novel approach to a highly sensitive and quantitative detection of rare earth element (REE) ions including La3+, Eu3+ and Tb3+, by the polymerase chain reaction (PCR) technique, has been reported. The detection of REE ions is based on the catalytic nature of REE ions targeting the deoxyribonucleic acid (DNA), thus monitoring of the ions can be achieved by reading the level of intact DNA by PCR. Despite of its high sensitivity (at ppb to ppt levels), the conventional PCR-based REE detection protocol requires certain length of time (1-2 hours). In the present study, we modified the PCR-based REE detection protocols by employing the high-speed PCR, and performed the automated and rapid detection of La3+ in small-sized aqueous samples within 5min.

An optical biosensor based on vegetal cells entrapped in an inorganic translucent matrix and fluorescence detection has been developed. The biosensor uses Chlorella vulgaris immobilized in a translucent support produced from sol–gel technology. The translucence of the structure enables the algal active layer to be placed directly in contact with the optical fibers for fluorescence detection. This configuration has many advantages over the use of an opaque support because no space between the optical fibers and the active layer is required to collect fluorescence. This reagentless biosensor allows determination of diuron as an anti-PSII herbicide and its long term activity is assessed.

While most microbes play an important role in nature, certain potentially harmful microbes can contaminate food and water, and cause a plethora of infectious diseases in both animals and humans. Conventional methods for detecting microbial contamination have primarily ...

We have developed a method for fabricating bacterial colony arrays and complex patterns using commercially available ink-jet printers. Bacterial colony arrays with a density of 100 colonies/cm2 were obtained by directly ejecting Escherichia coli (E. coli) onto agar-coated substrates at a rapid arraying speed of 880 spots per second. Adjusting the concentration of bacterial suspensions allowed single colonies of viable bacteria to be obtained. In addition, complex patterns of viable bacteria as well as bacteria density gradients were constructed using desktop printers controlled by a simple software program. © 2003 Wiley Periodicals, Inc.

The development of a highly selective and sensitive sensor for H2O2 in beverages such as natural juices, is described in this work. The sensor is based on the deposition of Prussian Blue (PB) onto screen-printed carbon electrodes (SPCEs) followed by the electropolymerization of a non-conducting film. Several procedures for PB deposition on the SPE electrodes were tested: electrochemical deposition (potentiostatic, cyclic voltammetry) and chemical deposition. The electrochemical and analytical properties of the SPCE/PB sensors had been evaluated and the potentiostatic method for PB deposition was selected for the further development of the H2O2 sensor. In order to develop a robust sensor for H2O2 determination in samples with complex matrix, we covered the PB layer with an electropolymerized non- conducting film with a high permselectivity for H 2O2. This film is a copolymer based on 2,6-DHN (2,6- dihydroxynaphtalene) and APEA (2-(4-aminophenyl)-ethylamine). The SPCE/PB/copolymer sen...

Conducting polymers can be exploited as an excellent tool for the preparation of nanocomposites with nano-scaled biomolecules. Polypyrrole(Ppy) is one of the most extensively used conducting polymers in design of bioanalytical sensors. In this review article significant attention ispaid to immobilization of biologically active molecules within Ppy during electrochemical deposition of this polymer. Such unique properties ofthis polymer as prevention of some undesirable electrochemical interactions and facilitation of electron transfer from some redox enzymes are discussed. Recent advances in application of polypyrrole in immunosensors and DNA sensors are presented. Some new electrochemical targetDNA and target protein detection methods based on changes of semiconducting properties of electrochemically generated Ppy doped by affinityagents are introduced. Recent progress and problems in development of molecularly imprinted polypyrrole are considered.

This paper reports on the high sensitivity of sub-spherical In 2 O 3-Pt nanoparticles (NPs) for detecting ppb levels of acetone, a biomarker for diabetes. The In 2 O 3-Pt NPs, in the form of monodisperse metal-oxide In 2 O 3 NPs with diameters of 6–8 nm, decorated with 2 wt% Pt metal NPs (2–3 nm) on the surface, were synthesized by a novel non-aqueous sol–gel route. NPs samples were investigated by X-ray powder diffraction (XRPD), using the advanced whole powder pattern modeling (WPPM) method, and high-resolution transmission electron microscopy (HR-TEM). The advantage of this preparative process is that it preserves metallic platinum NPs formed during the synthesis. The highly sensitive acetone sensor based on these NPs, showed a lower detection limit as low as 10 ppb or less, which is the lowest detection limit ever reported for any chemoresistive acetone sensors. This exceptional performance is likely due to the key role played by very small Pt metal NPs uniformly distributed in the In 2 O 3-Pt nanostructure. The developed sensor would be suitable for use as a highly sensitive, practical breath acetone checker for daily diet and diabetes management and diagnosis.

Biosensor is a bio-analytical integrated device that uses a biological detection system to target molecules or macromolecules. Biosensors can provide specific quantitative and semi quantitative analytical information using biological recognition by coupling to a physiochemical transducer which converts this recognition into a detectable output signal.  The characteristic features of a biosensor are linearity, sensitivity, selectivity and response time. Biosensors have potential applications beginning with medical, pharma, environmental, biodefence and food & beverage and have now extensive applications in health care. Biosensors are involved in molecular diagnosis, crime detection, drug development, food analysis, industrial process control, environmental field monitoring, detection systems in biological warfare agents and in manufacturing of pharmaceuticals and organ replacement. Biosensors have firmly established their applications in health care in the measurement of blood metabolites such as glucose, lactate, urea and creatinine, diabetes therapy, cardiovascular disease biomarkers and cancer biomarkers. This review mainly focuses on the recent advances and applications of biosensors in health care.

This review article focuses on several approaches in the characterization and modification of carbon surfaces
with electrocoated thin films which has been realized by recent progress in experimental methods.
Electropolymerization and electrocopolymerization of -conjugated polymers (pyrrole, carbazole, Nvinylcarbazole
and aniline) onto carbon surfaces are reviewed with 348 references. Particular emphasis
is placed on the recent nanoscale surface characterization techniques applied to the resulting electrocoated
polymers onto carbon fibers (i.e., scanning electron microscopy (SEM), cyclic voltammetry (CV),
X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), focused ion beam-secondary ion
mass spectroscopy (FIB-SIMS), Fourier transformed infrared spectroscopy (reflectance-FTIR), and Raman
spectroscopic measurements).
The electrochemical deposition of conducting polymers on carbon substrates has been studied with the
goal of improving the properties of these polymers so as to use them as electrodes in different applications:
batteries, sensors, capacitors or electrochromic displays. The synthesis and characterization of high
surface area nanomaterials, such as nanotubes and nanowires, have been carried out extensively in the
past few years. The electrochemical doped process of polypyrrole, polycarbazole, poly(N-vinylcarbazole)
and polyaniline thin films on carbon surfaces in different solutions has been investigated in this review
article.
We suggest guidelines that can be applied to a range of in vivo microsensor applications for evaluation
of analyte identification and improvement of selectivity. Various modified materials have been used on
carbon-based electrodes to investigate and detect biologically important redox species, which biosensors
represent a broad area of technology useful for environmental, food monitoring and clinical applications.