Electrochemiluminescence at 3D Printed Titanium Electrodes

Molecular dynamics simulation of the interaction between monofluoronitrobenzene and Ti electrode

In the process of degradation of aqueous fluoro-nitrobenzene (FNB) solution by titanium (Ti) electrode, the interaction between aqueous FNB solution and Ti electrode has an important impact on the performance and catalytic performance of electrode materials. The interaction involves complex physical, chemical and physical chemical processes, however, the mechanism of action is still unclear. In this study, Materials Studio software was used to design and construct molecular models of the interactions between aqueous FNB (p-, m-, o-FNB) solutions and Ti electrode, and molecular dynamics (MD) simulation was carried out in the absence of applied electric field and external electric field of 0.02 V/Å, respectively. Density functional theory (DFT) method was used to calculate the frontier molecular orbitals of three FNB molecules. Based on the calculation and analysis of the interaction energy (ΔE), diffusion coefficient (D) and radial distribution function (RDF), the interaction mechanism was discussed. It provides a theoretical basis for further research and development of Ti electrode degradation of fluorine compounds. The results showed that the order of ΔE between the three different aqueous FNB solutions and Ti surface is m-FNB > p-FNB > o-FNB when there is no external electric field. Under electric field of 0.02 V/Å, the order is p-FNB > m-FNB > o-FNB. The substitution position of F has an important effect on the HOMO of the nitro group and the LUMO of C-H in the three FNB molecules, and also affects the chemical reaction activity. In the model system, the diffusivity of different FNB solutions with electric field is less than that without electric field. The presence of an external electric field makes the diffusion of water and FNB molecules more orderly. The analysis results of RDF show that the bonding interactions between different FNB molecules and Ti surface is not much different before 3.5 Å, and all of them are weak. At about 8 Å, FNB molecule forms a non-bond with Ti electrode. ΔE, D and RDF of the model system can be changed by applying a certain external electric field, and the results are in better agreement with the experimental results.

Smartphone-based 3D-printed electrochemiluminescence enzyme biosensor for reagentless glucose quantification in real matrices

Three-dimensional (3D) printed electrochemical devices are increasingly used in point-of-need and point-of-care testing. They show several advantages such as simple fabrication, low cost, fast response, and excellent selectivity and sensitivity in small sample volumes. However, there are only a few examples of analytical devices combining 3D-printed electrodes with electrochemiluminescence (ECL) detection, an electrochemical detection principle widely employed in clinical chemistry analysis. Herein, a portable, 3D-printed miniaturized ECL biosensor for glucose detection has been developed, based on the luminol/H₂O₂ ECL system and employing a two-electrode configuration with carbon black-doped polylactic acid (PLA) electrodes. The ECL emission is obtained by means of a 1.5V AA alkaline battery and detected using a smartphone camera, thus providing easy portability of the analytical platform. The ECL system was successfully applied for sensing H₂O₂ and, upon coupling the luminol/H₂O₂ system with the enzyme glucose oxidase, for glucose detection. The incorporation of luminol and glucose oxidase in an agarose hydrogel matrix allowed to produce ECL devices preloaded with the reagents required for the assay, so that the analysis only required sample addition. The ECL biosensor showed an excellent ability to detect glucose up to 5 mmol L^-1, with a limit of detection of 60 μmol L^-1. The biosensor was also used to analyse real samples (i.e., glucose saline solutions and artificial serum samples) with satisfactory results, thus suggesting its suitability for point-of-care analysis. Coupling with other oxidases could further extend the applicability of this analytical platform.

Electrochemiluminescence Systems for the Detection of Biomarkers: Strategical and Technological Advances

Electrochemiluminescence (ECL)-based sensing systems rely on light emissions from luminophores, which are generated by high-energy electron transfer reactions between electrogenerated species on an electrode. ECL systems have been widely used in the detection and monitoring of diverse, disease-related biomarkers due to their high selectivity and fast response times, as well as their spatial and temporal control of luminance, high controllability, and a wide detection range. This review focuses on the recent strategic and technological advances in ECL-based biomarker detection systems. We introduce several sensing systems for medical applications that are classified according to the reactions that drive ECL signal emissions. We also provide recent examples of sensing strategies and technologies based on factors that enhance sensitivity and multiplexing abilities as well as simplify sensing procedures. This review also discusses the potential strategies and technologies for the development of ECL systems with an enhanced detection ability.

Research on advanced methods of electrochemiluminescence detection combined with optical imaging analysis for the detection of sulfonamides

In this study, a novel method that combines electrochemiluminescence (ECL) analysis and digital image processing was developed for the detection of sulfonamides. This method is based on the ECL system of ruthenium terpyridine, with 1 mM tripropylamine as a co-reactant to enhance the performance. Under the optimal conditions comprising a solution of pH 7 and a scanning rate of 0.08 V s^-1, the Pt electrode has an excellent linear detection range from 5 μM to 5 mM, with a detection limit of 0.85 μM (S/N = 3). A wireless camera is used to record the light-emitting process. The recordings are processed, and the digital images are extracted using image-processing algorithms implemented in Python to calculate the brightness value of the image, which has a linear relationship with the logarithm of the sulfonamide concentration. Image analysis simplifies and improves the stability of the ECL analysis process, while also increasing the speed of analysis. The results indicate that the method can successfully detect a sulfonamide concentration of 5 μM. Thus, the analysis method of ECL combined with image processing is feasible for the detection of sulfonamides, thereby displaying its potential applicability as a novel method in drug and food safety, for instance, for sulfonamide detection in antibiotics.