Welcome to the site!  The focus of our work is using dynamic multivariate optical spectroscopy to monitor interactions between small molecules in complex media and simultaneously measure the components of mixtures, e.g. toxins or pharmaceuticals, in environmental and biological samples. We focus on combining multichannel spectrochemical measurements with multivariate signal processing methods to generate the enhanced selectivity required to simultaneously monitor multiple solutes in heterogeneous microenvironments.  

        The long-term goals of this work include 1) the development of multivariate measurement technologies; 2) development of model-independent signal processing and data analysis methods to maximize information recovery and isolate individual solute responses and interactions in analytical samples and realistic model media;     3) detailed photokinetic/photochemical analysis of analyte mixtures and multi-state probes; and 4) characterization of lipid mixtures for use as biomimetic media in spectroscopic measurements.

        The synopses below provide links to longer descriptions of ongoing and new research projects that pursue these goals.  If you have questions that are not answered here or desire additional information, Prof. Neal can be contacted at sneal@udel.edu or (302)831-1948 (lab) or (302)831-0719 (office).


New Multivariate Spectroscopic Measurements

The combination of tunable laser excitation, multi-channel detection and computer control of spectrometer components allows us merge several spectroscopic measurements into multivariate measurements with the enhanced selectivity needed to study complex systems. (more...)

Model-Independent Data Analysis Methods 

Multivariate data sets are amenable to matrix and tensor analysis methods that separate the responses of mixtures into components without a priori knowledge of the number of components or specifics of their spectral properties. (more ...)

Characterization of Biomimetic Organized Media

The organized media that form spontaneously by self-assembly of lipid mixtures not only exhibit intriguing macroscopic properties because of their molecular scale order they provide a heterogeneous aqueous environment similar to vertebrate cell walls for chemical investigations and analysis. (more ...)

Photokinetic Analysis of Multi-State Probes

The emission of multi-state probes varies with microenvironment properties. Maximizing the utility of this feature to monitor the dynamics of microheterogeneous systems depends on thorough, accurate analysis of the photokinetic behavior of the probe. (more ...)

Phototoxicity of PAH mixtures

Polycyclic aromatic hydrocarbons (PAHs aka polynuclear aromatic hydrocarbons) are produced by incomplete combus-tion of fossil fuels, and consequently, are ubiquitous in the environment. The carcinogeneity of some PAHs has been studied for many years, but PAH phototoxicity and the toxicity of their photoreaction products have not received as much attention, particularly in mixtures. We are starting new projects in this exciting, multidisciplinary area and will update the site soon.


Contact: S.L. Neal

Location:  163 Brown Lab

Phone:  (302)831-1948

Multivariate Optical Spectroscopy


The Exploratorium, 1994.