NanoUV-VIS: An Interactive Visualization Tool for Monitoring the Evolution of Optical Properties of Nanoparticles throughout Synthesis Reactions

Abstract

Engineered nanoparticles (NPs) are being used for a broad array of high-technology applications,including sensing, imaging, targeted drug delivery, biodiagnostics, catalysis, optoelectronics, and film growth seeding [1, 2]. The enhanced optical, electrical, and catalytic properties of metal NPs are strongly correlated with their size, shape, and structure [3]. As such, physicochemical characterization of NPs is critically important to ensure their effective use and applicability. In this context, ultraviolet-visible spectroscopy (UV-VIS) is one of the most widely used methods for measuring the optical properties and electronic structures of NPs [4]. UV-VIS absorption bands are related to important properties such as the diameter [5], shape [2], and polydispersion [6] of metallic and semiconductor NPs. Thus, this analytical technique is used during NP synthesis to monitor NP formation, to assess suspension stability under different conditions and media [7, 8], and to establish the optical properties of the newly formed nanomaterials [9]. In view of the extensive use of UV-VIS for NP characterization and monitoring of NP formation during synthesis reactions, we developed NanoUV-VIS, an interactive web application designed for the analysis of multiple UV-VIS absorbance spectra measured as a function of time. Graphical visualizations of the data in two dimensions (spectrum plot, contourplot) and three dimensions (surface plot) are created by this tool. In addition, the NanoUV-VIS tool evaluates and estimates important parameters related to the absorption bands of NPs, including maximum optical absorbance, surface plasmon resonance (SPR) peak, and the full width at half maximum (FWHM) of the UV-VIS spectra. This information is available to download as a table in the software, as well as in the form of interactive plots, where the scientist can compare the behavior of these parameters in order to better interpret the outcomes of the experiment. Though NanoUV-VIS was designed to visualize NP synthesis, this tool can be used for a wide range of other applications in nanotechnology and nanoscience, such as the assessment of suspension stability, the investigation of the influence of coating agents on the NP optical properties, and the monitoring of seed-mediated NP synthesis, among others. Moreover, this data analysis and visualization tool can be extended to other fields beyond nanotechnology in which spectrochemical analysis by UV-VIS plays an important role.