Background: In this work, an aptamer-based biosensor was successfully developed based on the salt-induced gold nanoparticle (AuNP) Aggregation phenomenon for the detection of carbohydrate antigen 125 (CA125), which is an important tumor marker for ovarian cancer. Materials and Methods: Citrate-coated AuNPs are relatively highly dispersed NPs. In the presence of different salts, the electrostatic stability of NPs is reduced, and depending on the type of salt and its concentration, different degrees of Aggregation occur. On the other hand, the aptamer is easily adsorbed on the AuNP surface and can prevent salt-induced AuNP Aggregation. This phenomenon was used in this study to develop a simple biosensor for the detection of CA125. Results: In the presence of CA125, the aptamer was desorbed from the AuNP surface to bind to its antigen due to the higher affinity, leading to the Aggregation of AuNPs and a change in the absorption spectra of the solution. Under the optimum condition, the fabricated aptasensor showed a linear range of 15-160 U/mL with a limit of detection (LOD) of 14.41 U/mL. Conclusion: The aptasensor exhibited good repeatability with notable selectivity with regard to CA125 detection, even in human serum samples, as compared to the enzyme-linked immunosorbent assay (ELISA). In conclusion, the engineered aptasensor can serve as a promising tool for the simple, rapid, and cost-effective detection of CA125.

AuNP/TiO2 nanocomposite is promising for developing visible-light-induced plasmonic photocatalysis. The effective hot electron generation and inhabitation of electron-hole recombination are the paradigms for the efficiency of plasmonic photocatalysis. The photon-energy alteration in AuNP/TiO2 depends upon the shape, size, TiO2 phase, and crystallinity, irradiation wavelength, etc. For its movement, there are different suggestions, such as electron-phonon interaction, direct electron transfer, PRET, PIRET, remote activity mechanism, charge transfer mechanism, plasmon heating, Forster resonance energy transfer, etc.  Here, such different parameters and various physical mechanisms for its generation and role in the plasmon-induced photocatalysis by AuNP/TiO2 are being reviewed.

Background: Antithrombotic therapy, such as acetylsalicylic acid (ASA) and clopidogrel, may interfere with platelet Aggregation in thrombotic strokes. Therefore, a platelet Aggregation test is essential for monitoring therapy. A previous study observed a decrease in platelet Aggregation using antithrombotics with a manual LTA analyzer. Further research is required to compare this with an automatic tool to determine whether both instruments have similar detection capabilities.Methods: PPP and PRP samples were collected from 30 thrombotic stroke outpatients and 30 healthy controls. Platelet Aggregation tests were performed using ADP 5µM and Collagen 2µg/mL on both instruments, Chronolog® Model 490, and Sysmex® CS-2500. The tests were then analyzed using the Wilcoxon test for differences, the Spearman test for correlation, and the Bland-Altman analysis for agreement.Results: No differences were observed in MA values and numerical alignment between the two instruments for ADP and Collagen. If the MA result for the platelet Aggregation test on Chrono-log® Model 490 was high, it was likewise high on Sysmex CS-2500 and vice versa. Although the values of LP and Vel differed, the numbers for ADP and Collagen in both instruments were consistent.Conclusion: The comparison between both instruments indicates good agreement. Automated LTA demonstrates the same suitability as manual LTA and can be applied in clinical routines to assess platelet Aggregation function. Due to many variations in the pre-analytics stage that might affect the results, it is vital to standardize both the pre-analytics, analytics, and post-analytics stages to compare platelet Aggregation tests on the two instruments.