Plenary 3 2018
Near Infrared Spectral Imaging: from the macro- to the micro-scale and beyond
Abstract : Spectral Imaging expands NIR spectroscopy into the spatial domain through acquisition of spatially contiguous spectra over a sample surface. This technique enables investigation of the spatial distribution of bio-chemical components on or within a sample. NIR spectral images can be obtained using different modalities, such as transmission, reflectance, transflectance or interactance, and at various spatial scales, with pixel sizes ranging in size from millimetres to microns. More recently, darkfield NIR spectral imaging has been developed for characterisation of NIR scattering spectra of nanometre sized objects, such as cells and nanoparticles. This flexibility has widened the scope for potential applications in the biosciences, for example food quality analysis, pharmaceutical quality control, agricultural analysis and tissue characterisation. Regardless of the application, many common challenges are shared by practitioners of this technique, such as instrument selection, sample presentation and data analysis. These challenges are illustrated here through the presentation of case studies from our laboratory, including: spatially registered macroscopic and microscopic characterisation of biomaterials; time series analysis of biopolymers to characterise their stability and interaction with water and darkfield NIR spectral imaging of tissue and cells to enhance knowledge of their microenvironment and response to various treatments.