Validation of an electrochemical sensor based on gold nanoparticles as a point-of-care test for quantitative determination of glycated hemoglobin.

Monitoring the level of glycated hemoglobin (HbA1c) has become the gold standard measure for diabetes mellitus (DM) diagnosis and control, used in conjunction with fasting blood glucose (FBG) and oral glucose tolerance test. This study aimed to investigate the applicability of a newly developed nanoparticle-based electrochemical sensor-multiwalled nanotubes incorporated with gold nanoparticles (POCT-HbA1cMWCNTs/AuNPs)-used as a routine point-of-care test (POCT) for detection of HbA1c for the diagnosis of DM. Finger-prick and venous blood samples were collected from 108 DM and 98 non-DM subjects to determine HbA1c and total hemoglobin by POCT-HbA1cMWCNTs/AuNPs compared with the standard HPLC method. The performance of the POCT-HbA1cMWCNTs/AuNPs was evaluated using the standard cut-off HbA1c level of >6.5%. The test's sensitivity, specificity, positive predictive value, and negative predictive value were 100.00%, 90.32%, 87.23%, and 100.00%, respectively. The probability of DM diagnosis in a subject with HbA1c >6.5% (positive predictive value) was 87.23% (82/94). The accuracy of the POCT-HbA1cMWCNTs/AuNPs was 94.18%, with a %DMV (deviation from the mean value) of 0.25%. The results indicate satisfactory assay performance and applicability of the POCT-HbA1cMWCNTs/AuNPs for diagnosis of DM using the cut-off criteria of HbA1c >6.5.

Biogenic synthesis of gold nanoparticles mediated by Spondias dulcis (Anacardiaceae) peel extract and its cytotoxic activity in human breast cancer cell.

Green synthesis is a new paradigm for the preparation of gold nanoparticles (AuNPs) due to its cost-effectiveness and favorable environmental impact. This study presented a simple phytosynthesis process for the preparation of AuNPs utilizing the aqueous peel extract of Spondias dulcis (SPE) (Anacardiaceae) as both a reducing and stabilizing agent. A visual color change from yellow to purple during the reaction implied the successful formation of SPE-AuNPs, which was confirmed by UV-vis spectroscopy. Transmission electron microscopy (TEM) images indicated that the SPE-AuNPs were predominantly spherical with a mean size of 36.75 ± 11.36 nm, and were comprised of crystalline Au, as indicated by X-ray diffraction. In terms of their potential application, SPE-AuNPs exhibit significant cytotoxic activity in a dose- and time-dependent manner to MCF-7 human breast cancer cells, while being non-toxic to Vero normal cells. The treatment of MCF-7 cells with SPE-AuNPs increased the production of intracellular reactive oxygen species (ROS). Herein, the findings highlight the potential contribution of phytosynthesized SPE-AuNPs to the development of novel nanomedicines for cancer treatment.