Multienergy Calibration Applied for the Quantification of Polymer Concentration in Conjugated Polymer Nanoparticles

Multienergy calibration (MEC) is an innovative analytical method to determine the analyte concentration in atomic spectroscopy. Recently, the MEC's applicability for quantifying molecular species by ultraviolet-visible (UV- vis) absorption and fluorescence was demonstrated, showing higher precision and sensitivity in the determination of analyte concentration than the standard methods such as standard calibration and standard addition. In this work, MEC is shown to be a suitable method for quantifying the concentration of a conjugated polymer in conjugated polymer nanoparticles (CPNs). The proof of concept of this approach is demonstrated by analyzing CPNs containing poly(2,5-di(hexyloxy)cyanoterephthalylidene) and poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cy-clopenta-[2,1-b;3,4-b0]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] using UV- vis absorption measurements. The results are comparable to those obtained with the conventional external calibration method but with improved limits of detection and quantification. Additionally, MEC is less labor-intensive because of the reduced need to prepare multiple calibration standards and allows aqueous sample analysis.