In response to the escalating challenges of counterfeiting due to technological and socioeconomic advancements, a novel trilevel anti-counterfeiting Quick Response (QR) code system has been developed. This system integrates digital polymers with QR code and stimulus-responsive chromophores,
Herein, a novel, recognition-molecule-free electrode based on Ti3C2/TiO2 composites was synthesized using Ti3C2 as the Ti source and TiO2 in situ formed by oxidation on the Ti3C2 surface for the selective detection of dopamine (DA). The TiO2 in situ formed by oxidation on the Ti3C2 surface not only increased the catalytically active surface for DA binding but also accelerated the carrier transfer due to the coupling between TiO2 and Ti3C2, resulting in a better photoelectric response than pure TiO2. Through a series of experimental conditions optimization, the photocurrent signals obtained by the MT100 electrode were proportional to the DA concentration from 0.125 to 400 µM, with a detection limit estimated at 0.045 µM. We also monitored DA in human blood serum samples using the MT100 electrode. The results showed good recovery, demonstrating the promising use of the sensor for the analysis of DA in real samples.
The exploration of advanced photocatalysts for efficient N2 reduction reaction (NRR) by integrating facet-engineering and realistic N2 active sites is very promising, but it remains a challenge due to the absence of rational structural design and atomic-level insights into molecular N2 activation. Herein, the same main group transition metal (e.g., Co, Rh, and Ir) clusters were ingeniously modified onto the dominant {111} crystal facet of Cu2O nanocrystal, aiming to track the synergistic effect of various N2 active sites and facet-engineering for efficient N2 photofixation. Intriguingly, further theoretical studies reveal that the incorporating Ir clusters can improve light absorption ability, accelerate photogenerated charge separation and transfer, and lower the reaction energy barrier, thereby expressively promoting the real photoreactivity. The present work offers a promising approach to cooperatively regulate the facet-engineering and N2 active centers at the atomic level, expecting to guide innovative design of smart NRR systems.
A novel enzyme-free photoelectrochemical (PEC) potential measurement system based on Dy-OSCN was designed for ascorbic acid (AA) detection. The separation and transmission of internal carriers were accelerated and the chemical properties became more stable under light excitation due to the regular microstructure of the prepared Dy-OSCN monocrystal. More importantly, the PEC potential method (OCPT, open circuit potential-time) used in this work was conducive to the reduction of photoelectric corrosion and less interference introduced during the detection process, which effectively ensured the repeatability and stability of the electrode. Under optimal conditions, the monocrystal successfully served as a matrix for the detection of AA, and the prepared PEC sensor exhibited a wide linear range from 7.94 × 10−6 mol/L to 1.113 × 10−2 mol/L and a sensitive detection limit of 3.35 μM. Practical human urine sample analysis further revealed the accuracy and feasibility of the Dy-OSCN-based PEC platform. It is expected that such a PEC sensor would provide a new way for rapid and non-invasive AA level assessment in human body constitution monitoring and lays a foundation for the further development of practical products.