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Reproducibility and linearity are crucial benchmarks for any measurement technology. However, UV–vis and fluorescence spectral distortion and nonlinearity are prevalent, even in seemingly simple fluorescent solutions that comprise only one dissolved molecular fluorophore, without exogenous absorbing or scattering species. In this report, we introduce an analytical model for the quantification of fluorescence interference on UV–vis measurements and a conceptual model for mechanistically understanding the impacts of higher-order cascading optical processes on fluorescence measurements. The experimental UV–vis transmittance can be dominated by interfering fluorescence, even for fluorophore solutions with theoretical absorbance values far below the instrument’s linear dynamic range (LDR). Absorption-inner-filter-effect (aIFE) correction drastically improves the fluorescence LDR. However, the efficacy of aIFE correction hinges on two competing factors that strongly depend on the fluorophore’s optical properties: the degree of fluorescence interference in UV–vis and the significance of secondary or higher-order emission triggered by fluorophore absorption of emitted photons. Our research sheds light on the remarkable complexity of cascading optical processes that can occur even in the simplest fluorescent solutions. It emphasizes the necessity of critically evaluating optical spectroscopic measurements of fluorescent solutions to improve the reliability of analyzing and interpreting optical spectra. Moreover, it lays the groundwork for future development of methods capable of handling challenging samples that exceed the capabilities of the current tools.
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Advancing Evidence-Based Data Interpretation in UV−Vis and Fluorescence Analysis for Nanomaterials: An Analytical Chemistry Perspective
UV–vis spectrophotometry and spectrofluorometry are indispensable tools in education, research, and industrial process controls with widespread applications in nanoscience encompassing diverse nanomaterials and fields. Nevertheless, the prevailing spectroscopic interpretations and analyses often exhibit ambiguity and errors, particularly evident in the nanoscience literature. This analytical chemistry Perspective focuses on fostering evidence-based data interpretation in experimental studies of materials’ UV–vis absorption, scattering, and fluorescence properties. We begin by outlining common issues observed in UV–vis and fluorescence analysis. Subsequently, we provide a summary of recent advances in commercial UV–vis spectrophotometric and spectrofluorometric instruments, emphasizing their potential to enhance scientific rigor in UV–vis and fluorescence analysis. Furthermore, we propose potential avenues for future developments in spectroscopic instrumentation and measurement strategies, aiming to further augment the utility of optical spectroscopy in nano research for samples where optical complexity surpasses existing tools. Through a targeted focus on the critical issues related to UV–vis and fluorescence properties of nanomaterials, this Perspective can serve as a valuable resource for researchers, educators, and practitioners.
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- Award ID(s):
- 2203571
- PAR ID:
- 10522141
- Publisher / Repository:
- American chemical society
- Date Published:
- Journal Name:
- Analytical chemistry
- ISSN:
- 0003-2700
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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