Titanium dioxide nanoparticles have been drawing attention due to possible concerns for safety in consumer and food products. In addition to the aforementioned applications, there has been an increase in utilization of nano TiO2 in water treatments devices due to this material’s oxidative power. With utilization of nano enabled technology comes the risk for potential release from the treatment device. Hence, the need for low-cost analytical methods that can rapidly detect and quantify these nanoparticles, preferably on site. Current detection methods involve expensive analytical equipment, which may require complex sample preparation, and experienced technicians. This work presents the development of a simple and portable method to detect and quantify mass concentrations of TiO2 nanoparticles in treated drinking water. This portable method utilizes UV light to excite TiO2 particles, which then selectively hydroxylates terephthalic acid, producing fluorescent 2-hydroxyterephthalic probes in solution. Increased fluorescence intensity is directly correlated to increased concentrations of TiO2 nanoparticles in solution. The detection of three nanoscale TiO2 particles were tested in distilled, soft, and hard water matrices. The LOD and LOQ for this method were as low as 0.388 ppb and 1.30 ppb, respectively, in distilled water. These values increased in soft (2.12 & 7.07 ppb) and hard (64.3 & 214ppb) water formulations, respectively. In addition, the produced signal for 100ppb of TiO2 particles could maintain a 95% confidence interval in the presence of up to 703 ppb of humic acid. This current method demonstrates the powerful capabilities of an affordable and portable detection method for TiO2 nanoparticles in water.

Detecting TiO2 nanoparticles in drinking waters by fluorescent probes

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.