Probe technique-based generalized multivariate standard addition strategy for the analysis of fluorescence signals with matrix effects

Abstract

The presence of practically unavoidable matrix effects from the spectroscopically inactive compounds (which may enhance or suppress intensities of spectral measurements of samples) and background interference effects from the spectroscopically active compounds other than the analytes of interest in real-world complex samples can significantly affect the accuracy of quantitative results of optical chem/biosensing techniques, and hence greatly hinder their applications to real-world complex samples. In this contribution, a probe technique-based generalized multivariate standard addition strategy was designed for the analysis of fluorescence signals with both matrix effects and background interference effects. The performance of the proposed strategy was tested on a proof-of-concept system of quantifying Zn2+ in real-world samples such as rice and zinc gluconate oral solution using a selective fluorescence probe dansylaminoethyl-cyclen and compared with the classical univariate standard addition method. Experimental results demonstrated that one standard addition sample was enough for the proposed strategy to provide satisfactory quantitative results (consistent with the results of ICP-MS) for Zn2+ in the real test samples, which were by far better than the corresponding results of the classical univariate standard addition method. The main contributions of this research are 1) to greatly improve the accuracy of quantitative results of optical chem/biosensing techniques, and 2) to open up an avenue for quantitative analysis of small-volume biological samples or some precious samples using invasive techniques in fields such as biomedical sciences, clinical diagnosis and archeology, etc.