Trace lead analysis based on carbon-screen-printed-electrodes modified via 4-carboxy-phenyl diazonium salt electroreduction

D, Decorse P, Pinson J, Podvorica FI. Surface Modification of Lignite with Alkyl and Mixed Alkyl-Aryl Films Generated from an Aryl Diazonium Salt and Alkyl Halides: Experimental Results and Theoretical Analyses

In search of new possible uses of cheap lignite from the Kosova Bassin, the surface of lignite powders is modified with alkyl or mixed alkyl-aryl layers. Modification is performed in aqueous acid solution containing an aryl diazonium salt and an alkyl halide compound in millimolar concentration, in the presence of potassium iodide as a reducing agent at equimolar concentration. Attachment of alkyl films substituted with carboxylic groups and aryl films with nitro or bis-trifluoromethyl groups is characterized by IRATR and XPS spectroscopy. The formation of a stable interface during the grafting reactions of alkyl and aryl moieties with lignite surface has been confirmed by theoretical calculations. Aryl diazonium salts once chemically or spontaneously reduced are a source of aryl radicals, able to attach chemically to the material surface or to react with alkyl halides by abstracting the halogen atom. If the aryl diazonium salts are unable to graft to the coal surface due to steric hindrance, they can, nevertheless, abstract an iodine or bromine atom to generate alkyl radicals that react with the material surface.

Point-of-care biochemical assays using electrochemical technologies: approaches, applications, and opportunities

Against the backdrop of hidden symptoms of diseases and limited medical resources of their investigation, in vitro diagnosis has become a popular mode of real-time healthcare monitoring. Electrochemical biosensors have considerable potential for use in wearable products since they can consistently monitor the physiological information of the patient. This review classifies and briefly compares commonly available electrochemical biosensors and the techniques of detection used. Following this, the authors focus on recent studies and applications of various types of sensors based on a variety of methods to detect common compounds and cancer biomarkers in humans. The primary gaps in research are discussed and strategies for improvement are proposed along the dimensions of hardware and software. The work here provides new guidelines for advanced research on and a wider scope of applications of electrochemical biosensors to in vitro diagnosis.

Electrochemical Biosensors: A Solution to Pollution Detection with Reference to Environmental Contaminants

The increasing environmental pollution with particular reference to emerging contaminants, toxic heavy elements, and other hazardous agents is a serious concern worldwide. Considering this global issue, there is an urgent need to design and develop strategic measuring techniques with higher efficacy and precision to detect a broader spectrum of numerous contaminants. The development of precise instruments can further help in real-time and in-process monitoring of the generation and release of environmental pollutants from different industrial sectors. Moreover, real-time monitoring can also reduce the excessive consumption of several harsh chemicals and reagents with an added advantage of on-site determination of contaminant composition prior to discharge into the environment. With key scientific advances, electrochemical biosensors have gained considerable attention to solve this problem. Electrochemical biosensors can be an excellent fit as an analytical tool for monitoring programs to implement legislation. Herein, we reviewed the current trends in the use of electrochemical biosensors as novel tools to detect various contaminant types including toxic heavy elements. A particular emphasis was given to screen-printed electrodes, nanowire sensors, and paper-based biosensors and their role in the pollution detection processes. Towards the end, the work is wrapped up with concluding remarks and future perspectives. In summary, electrochemical biosensors and related areas such as bioelectronics, and (bio)-nanotechnology seem to be growing areas that will have a marked influence on the development of new bio-sensing strategies in future studies.

Advances on Aryldiazonium Salt Chemistry Based Interfacial Fabrication for Sensing Applications

Aryldiazonium salts as coupling agents for surface chemistry have evidenced their wide applications for the development of sensors. Combined with advances in nanomaterials, current trends in sensor science and a variety of particular advantages of aryldiazonium salt chemistry in sensing have driven the aryldiazonium salt-based sensing strategies to grow at an astonishing pace. This review focuses on the advances in the use of aryldiazonium salts for modifying interfaces in sensors and biosensors during the past decade. It will first summarize the current methods for modification of interfaces with aryldiazonium salts, and then discuss the sensing applications of aryldiazonium salts modified on different transducers (bulky solid electrodes, nanomaterials modified bulky solid electrodes, and nanoparticles). Finally, the challenges and perspectives that aryldiazonium salt chemistry is facing in sensing applications are critically discussed.

“One-drop-of-blood” electroanalysis of lead levels in blood using a foam-like mesoporous polymer of melamine–formaldehyde and disposable screen-printed electrodes

A foam-like mesoporous melamine–formaldehyde polymer was synthesized and deposited on disposable screen-printed electrodes for the electroanalysis of Pb²⁺ ions in blood.

Disposable screen printed electrochemical sensors: tools for environmental monitoring

Screen printing technology is a widely used technique for the fabrication of electrochemical sensors. This methodology is likely to underpin the progressive drive towards miniaturized, sensitive and portable devices, and has already established its route from "lab-to-market" for a plethora of sensors. The application of these sensors for analysis of environmental samples has been the major focus of research in this field. As a consequence, this work will focus on recent important advances in the design and fabrication of disposable screen printed sensors for the electrochemical detection of environmental contaminants. Special emphasis is given on sensor fabrication methodology, operating details and performance characteristics for environmental applications.