Aoife Gowen

• BA Theor Physics, MSc Maths, PhD Food Science
• Professor at University College Dublin

Plastic pollution, driven by micro- and nanoplastics (MNPs), poses a major environmental threat, exposing humans through various routes. Despite human colorectal adenocarcinoma Caco-2 cells being used as an in vitro model for studying the intestinal epithelium, uncertainties linger about MNPs harming these cells and the factors influencing adverse...

Despite the breadth of scientific literature on micro- and nanoplastics (MNPs), a standardized procedure for detecting MNPs is still lacking so far, leading to incomparable results between published studies. This work innovatively proposed the combination of machine learning with advanced optical photothermal infrared (O-PTIR) spectroscopy to devel...

Although the ingestion of microplastics by fish has been investigated extensively over the last 50 years, the quality of these ingestion studies is questionable due to the lack of standard methods for sampling, extraction, and identification of microplastics. This review aims to provide reliable results of microplastic occurrence in fish sourced fr...

Classical molecular-dynamics simulations have been performed to examine the interplay between ubiquitin and its hydration-water sub-layers, chiefly from a vibrational-mode and IR viewpoint—where we analyse individual sub-layers characteristics. The vibrational Density of States (VDOS) revealed that the first solvation sub-shell indicates a confined...

Deep learning (DL) is emerging as a new tool to model spectral data acquired in analytical experiments. Although applications are flourishing, there is also much interest currently observed in the scientific community on the use of DL for spectral data modelling. This paper provides a critical and comprehensive review of the major benefits, and pot...

A growing number of articles have been reported to investigate health consequences of micro- and nanoplastics (MNPs) exposure, but no coherent images have been achieved due to the incomparability between studies, the complexity and heterogeneity of the existing toxicity data of MNPs. Herein, this work developed a predictive modelling framework for...

This work investigates non-contact reflectance spectral imaging techniques, i.e. microscopic Fourier transform infrared (FTIR) imaging, macroscopic visible-near infrared (VNIR), and shortwave infrared (SWIR) spectral imaging, for the identification of bacteria on stainless steel. Spectral images of two Gram-positive (GP) bacteria (Bacillus subtilis...

This study applies the single drop techniques to compare the efficacy of Raman, FT – NIR, and FT-MIR spectral imaging to quantify lactose concentration in dried whole milk on different metallic surfaces. Drying the samples avoids degradation problems such as water evaporation or oil degradation and scattering due to micelles. Spectral imaging techn...

This systematic review aims to summarize the current knowledge on biological effects of micro- and nanoplastics (MNPs) on human health based on mammalian systems. An extensive search of the literature led to a total of 133 primary research articles on the health relevance of MNPs. Our findings revealed that although the study of MNP cytotoxicity an...

This chapter explores the key procedures for sampling, collection, identification, and quantification of the abundance of microplastics (MPs) particles in the marine environment. In marine ecosystems, MP debris exists ubiquitously in seawater, sediments, macrophytes, plankton, shellfish, and fish species. Physically separating the MPs from seawater...

This work investigates the application of reflectance Fourier transform infrared (FTIR) microscopic imaging for rapid, and non-invasive detection and classification between Bacillus subtilis and Escherichia coli cell suspensions dried onto metallic substrates (stainless steel (STS) and aluminium (Al) slides) in the optical density (OD) concentratio...

The addition of plastic substances in teabags is of increasing concern for conscious consumers due to the harmful effects on the environment and the potential threats to human health. This work introduces an innovative and cost-effective approach to detect and quantify plastic substances in teabags by applying near infrared hyperspectral imaging (9...

This paper addresses the underlying bottleneck of unknown materials and material characteristics for assessing the life cycle of an existing structure or considering interventions. This done by classifying and characterizing common building materials with two readily accessible, remote sensing technologies: multispectral imaging and Light Detection...

Molecular-dynamics simulations have been performed for full liquid water adsorbed onto two planar silicon surfaces, with varying hydrogen-and hydroxyl-termination (mimicking different extents of hydrophobicity and hydrophophilicity). It was found that there was water-density 'ordering' perpendicular to both surfaces-heavily dependent on the degree...

The objective of this study is to compare portable visible spectral imaging (443-726 nm) and conventional RGB imaging for detecting poultry stored beyond the recommended shelf life as indicated by the "use-by" date.

Time series spectral imaging facilitates a comprehensive understanding of the underlying dynamics of multi-component systems and processes. Most existing classification strategies focus exclusively on the spectral features and they tend to fail when spectra between classes closely resemble each other. This work proposes a hybrid approach of princip...

This work investigates the nature of the molecular interactions between water vapor and polymers using time series Fourier transform infrared (FTIR) spectroscopy. A detailed analysis of the frequency shifts and relative peak intensities led to the conclusion that polyvinyl alcohol (PVOH) sorbed a large quantity of water vapor molecules, resulting i...

Rapid detection of foodborne pathogens, spoilage microbes, and other biological contaminants in complex food matrices is essential to maintain food quality and ensure consumer safety. Traditional methods involve culturing microbes using a range of nonselective and selective enrichment methods, followed by biochemical confirmation among others. The...

Classical molecular-dynamics simulations have been performed to examine the intricacies and subtleties of the interactions between hen egg-white lysozyme (HEWL) and its interfacial-water layers, chiefly from a vibrational-mode perspective. It was found that the vibrational Density of States (VDOS) reveals that the lower-frequency region in the firs...

Correction for ‘Feasibility of attenuated total reflection-fourier transform infrared (ATR-FTIR) chemical imaging and partial least squares regression (PLSR) to predict protein adhesion on polymeric surfaces’ by S. Mukherjee et al. , Analyst , 2019, 144 , 1535–1545. DOI: 10.1039/C8AN01768A

A realistic risk assessment of microplastic pollution must stand on representative data on the abundance, size distribution and chemical composition of polymers. Infrared spectroscopy is an indispensable tool for the analysis of microplastics (<5 mm). Spectral imaging, which provides simultaneous measurement of spatial (e.g., particle morphology) a...

Biomaterials’ surface properties elicit diverse cellular responses in biomedical and biotechnological applications. Predicting cell behaviour on polymeric surface is an ongoing challenge due to its complexity. This work proposes a novel modelling methodology based on attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Sp...

Consumption of poultry products is increasing worldwide, leading to an increased demand for safe, fresh, high quality products. To ensure consumer safety and meet quality standards, poultry products must be routinely checked for faecal matter detection, food fraud, microbiological contamination, physical defects, and product quality. However, tradi...

The objective of this study is to use a handheld visible hyperspectral imaging (HSI) system (443-726 nm) to discriminate between fresh and previously frozen poultry at the object level using white LED illumination.

he aim of our study is to examine the potential of SWIR hyperspectral imaging to early detect apple scab infection. Close range hyperspectral images of healthy and infected leaves were acquired daily under laboratory conditions from 2 days to 11 days after inoculation using a push-broom SWIR camera. A PLS-DA classification model was built at the ad...

Bananito (Musa acuminata, AA) fruit in three maturity stages (stages 2, 4 and 6) were investigated in this study. Correlation analysis was conducted between fruit firmness, soluble solids content (SSC) and several colour parameters. Point-measured spectroscopy (Vis-point) and spatial-measured hyperspectral imaging (Vis-HSI) were applied to collect...

Despite a substantial body of research to date for the detection of microplastics (MPs) in almost every environmental compartment there remains a lack of standardisation, and methodologies used by different research groups vary widely. Chemical imaging, which provides simultaneous measurement of physical (i.e. spatial) and chemical (i.e. spectrosco...

This study was carried out to investigate the feasibility of an original polarized hyperspectral imaging setup in the spectral range of 400–1100 nm for enhancement of absorbance signal measurement on highly scattering samples. Spatial response and spectral calibration have been verified, indicating the consistency of this system and reliability of...

HIGHLIGHTS • How to evaluate model predictions from hyperspectral images? • We can use the spatial structure of prediction maps. • Spatially structured variance relates to the slope of the model. • Non spatially structured variance relates to the random error. ABSTRACT Applying a calibration model onto hyperspectral (HS) images is of great int...

This work explores the potential of multivariate PLSR modelling in conjunction with Attenuated Total Refl ection-Fourier Transform Infrared (ATR-FTIR) chemical imaging to investigate whether experimentally characterised surface chemistry can be used to predict surface protein adhesion. Our method can predict the degree to which protein adhesion occ...

This study aims to investigate the potential of an original polarized hyperspectral imaging (HSI) setup in the spectral domain of 400-1000 nm for sunflower leaves in real-world. Dataset 1 includes hypercubes of sunflower leaves in two varieties with different life growth stages, while Dataset 2 is comprised of healthy and contaminated sunflower lea...

Applications of hyperspectral imaging (HSI) to the quantitative and qualitative measurement of samples have grown widely in recent years, due mainly to the improved performance and lower cost of imaging spectroscopy instrumentation. Data sampling is a crucial yet often overlooked step in hyperspectral image analysis, which impacts the subsequent re...

Open access [https://www.impopen.com/jsi-abstract/I08_a3]. Milk is a complex emulsion of fat and water with proteins (such as caseins and whey), vitamins, minerals and lactose dissolved within. The purpose of this study is to automatically distinguish different dairy residues on substrates commonly used in the food industry using hyperspectral ima...

This paper evaluated the feasibility of using spectrometry data in the short-wave infrared range (1,300–2,200Â nm) to distinguish lime mortar and Type S cement mortar using 42 lab samples (21 lime-based, 21 cement-based) each 40×40×40Â mm were created. A Partial Least Squares Discriminant Analysis model was developed using the mean spectra of 28 sp...

This study aims to investigate the potential of an original polarized hyperspectral imaging (HSI) setup in the spectral domain of 400-1000 nm for sunflower leaves in real-world. Dataset 1 includes hypercubes of sunflower leaves in two varieties with different life growth stages, while Dataset 2 is comprised of healthy and contaminated sunflower leaves...

Surface chemistry of polymeric surfaces is one of the variables determining the subsequent interaction of the surface with biomolecules. However, predicting the degree to which proteins adhere to a polymeric surface is an ongoing challenge in the scientific community to prevent non-specific protein adhesion and drive favourable protein-surface inte...

This paper describes the feasibility of using short-wave infrared (SWIR) spectrometry to classify concretes by their water-to-cement (w/c) ratios and predict their density. Concrete spectra of three w/c ratios (50%, 65%, 80%) were studied in the 1300–2200 nm range. A Partial Least Square Discriminant Analysis model was developed from the spectra of...

This work aims to investigate the emergence of aggregates caused by redundant plasticizers in the protein matrix of casein based biopolymers using chemical imaging techniques. Near infrared (NIR) images (950–1671 nm) were first acquired and the spatial variations on macroscale with a pixel size of 0.4 mm × 0.5 mm were visualized. The introduction o...

The present study investigated spatial heterogeneity in magnesium oxychloride cements within a model of a mould using hyperspectral chemical imaging (HCI). The ability to inspect cements within a mould allows for the assessment of material formation in real time in addition to factors affecting ultimate material formation. Both macro scale NIR HCI...

Photo-induced enhanced Raman spectroscopy from a lithium niobate on insulator (LNOI)-silver nanoparticle template is demonstrated both by irradiating the sample with 254 nm UV light before adding an analyte and before placing the sample in the Raman system (substrate irradiation) and by irradiating the sample in the Raman system after adding the mo...

Characterizing material strength in-situ for existing structures poses a major problem for a range of civil engineering applications including structural modelling for tunnelling-vulnerability assessment and pre-earthquake resiliency evaluation, especially for unreinforced masonry buildings. Present methods require expensive testing equipment often...

The static water contact angle (CA) quantifies the degree of wetting that occurs when a surface encounters a liquid, e.g. water. This property is a result of factors such as surface chemistry, local roughness and is an important analytical parameter linked to the suitability of a surface for a given bioanalytical process. Monitoring spatial variati...

Both near infrared hyperspectral imaging (NIR-HSI) and Raman hyperspectral imaging (R-HSI) were investigated in combination with multivariate analysis to assess binary mixtures of food powders. NIR-HSI and R-HSI data of corn flour (CF), icing sugar (IS) and binary mixtures of both in concentrations of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%...

Carbon based nanomaterials offer the potential to provide solutions to key technological challenges. This work describes the preparation of luminescent carbon nanofibers by template-assisted microwave pyrolysis of environmentally friendly precursors, citric acid and polyethyleneimine, in aqueous solution. SEM reveals a dense forest of vertically al...

Statement of significance: The human body is an aggressive environment for implantable devices and their biomaterial components. Polycarbonate urethane (PCU) biomaterials in particular were investigated in this study. Traditionally one or a few points on the PCU surface are analysed using ATR-FTIR spectroscopy. However the selection of acquisition...

Calibration transfer from a handheld micro NIR spectrometer (NIR-point, 939–1602 nm, 6.2 nm) to a desktop hyperspectral imaging (NIR-HSI) for predicting soluble solids content (SSC) of bananito flesh was investigated in the study. Different spectral pre-processing and standardization methods were employed for correcting spectra so as to minimise sp...

Array detectors improve data collection speed in hyperspectral chemical imaging, yet are prone to striping noise patterns in the image plane, which is difficult to remove. This type of noise affects spectral features and disturbs visual impression of the scene. We found that this type of noise depends on the material composition and setting paramet...

Imaging spectroscopy integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Processing and analysis of a hypercube can be a hard task. Robust methods for hyperspectral data classification are required, insensitive to imaging deficiencies and high input dimension. Mushrooms have a thin and po...

Hydrogels are an important class of biomaterials that can absorb large quantities of water. In this study, changes in hydration of natural hydrogels (agar, chitosan, gelatin, starch, and blends of each with chitosan) during storage and rehydration were studied by using near-infrared hyperspectral imaging (NIR-HSI). Moisture content was calculated b...

Molecular-dynamics simulations for silicon, hydrogen-and hydroxyl-terminated silicon in contact with liquid water, at 220 and 300 K, display water-density 'ordering' along the laboratory z-axis, emphasising the hydrophobicity of the different systems and the position of this first adsorbed layer. Density of states (DOS) of the oxygen and proton vel...

This present work aims to provide new insights into the spectral variations associated with water and plasticizers in the protein matrix of casein based biopolymers by conducting time series hyperspectral chemical imaging (HCI). Near infrared (NIR) hyperspectral images (880-1720 nm) of sodium caseinate film were acquired at different periods during...

This study investigates the potential use of attenuated total internal reflection-Fourier transform infrared (ATR-FT-IR) imaging, a hyperspectral imaging modality, to investigate molecular level trends in the interaction of water with polymeric surfaces of varying hydrophobicity. The hydrophobicity of two categories of polymeric biomaterials is cha...

This study investigates the potential use of attenuated total internal reflection-Fourier transform infrared (ATR-FT-IR) imaging, a hyperspectral imaging modality, to investigate molecular level trends in the interaction of water with polymeric surfaces of varying hydrophobicity. The hydrophobicity of two categories of polymeric biomaterials is cha...

The aim of this study was to investigate the potential of the recently developed ensemble Monte Carlo Variable Selection (EMCVS) method to identify the relevant portions of high resolution ¹H NMR spectra as a metabolite fingerprinting tool and compare to a widely used method (Variable importance on projection (VIP)) and recently proposed variable s...

Hyperspectral image data set here: http://www.ucd.ie/biowater/datasets/

Data set available here: http://www.ucd.ie/biowater/datasets/

Chemical image fusion refers to the combination of chemical images from different modalities for improved characterisation of a sample. Challenges associated with existing approaches include: difficulties with imaging the same sample area or having identical pixels across microscopic modalities, lack of prior knowledge of sample composition and lac...

A hyperspectral image is a large dataset in which each pixel corresponds to a spectrum, thus providing high-quality detail of a sample surface. Hyperspectral images are thus characterised by dual information, spectral and spatial, which allows for the acquisition of both qualitative and quantitative information from a sample. A hyperspectral image,...

This review focuses on the recent developments in vibrational spectroscopy and chemical imaging (i.e. Raman, Near Infrared, Mid Infrared) to characterize polymers in diverse forms, their behaviour and transient phenomenon. First, important polymeric properties and traditional methods of their characterization are outlined. Then relative advantages...

Mealiness is known as an important internal quality attribute of fruits/vegetables, which has significant influence on consumer purchasing decisions. Mealiness has been a topic of research interest over the past several decades. A number of destructive and nondestructive techniques are introduced for mealiness detection. Nondestructive methods are...

The poor of the world depends directly on water and other natural resources for their livelihoods. Water resources must therefore be managed in a sustainable manner in order to maintain the economic, social and environmental functions and to contribute to the livelihoods of people. 2 - Advancements in sensor technologies and processing algorithms h...

Near-infrared (NIR) chemical imaging is an emerging technique with the potential for the detection of contaminants in the environmental field. In this study the potential of NIR chemical imaging (NIR-CI) to predict concentrations of nutrients (total nitrogen, total phosphorus) and indicator microorganisms (Escherichia coli) in surface water was inv...

Moisture content and water activity are key parameters in predicting the stability of low moisture content products. However, conventional methods for moisture content and water activity determination (e.g., loss on drying method, ‎Karl Fischer titration, dew point method) are time consuming, demand specialized equipment and are not amenable to onl...

Quantification or classification is a key objective of hyperspectral chemical imaging (HCI). In this chapter, steps involved in the development of classification and prediction models from HCI data are explained, from initial data pretreatment, through to calibration set development and construction of prediction maps using partial least squares di...

The advantages of hyperspectral imaging (HSI) which is an emerging platform technology that integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object will be discussed. Although HSI was originally developed for remote sensing, it has recently emerged as a powerful process analytical tool for non...

Keynote presentation at HSI 2014

Invited presentation at AnalytiX 2014

Welcome to the second instalment of our series on hyperspectral image analysis This tutorial will focus on getting to grips with the basic manipulation of hyperspectral images: rearrangement of data values, basic visualisation, selection and extraction of spectra.

Hyperspectral chemical imaging (HSI) is a broad term encompassing spatially resolved spectral data obtained through a variety of modalities (e.g. Raman scattering, Fourier transform infrared microscopy, fluorescence and near-infrared chemical imaging). It goes beyond the capabilities of conventional imaging and spectroscopy by obtaining spatially r...

Welcome to the third instalment of this series on hyperspectral image analysis using R. At this stage, I hope you are familiar with the basic workings of R, and feel ready to get started with some more analysis. In this issue, I will take you through some rather basic methods for classifying objects in a hyperspectral image, using the same sample i...

Calibration models developed from hyperspectral imaging data may be applied at the pixel level to generate prediction maps that estimate the spatial distribution of components in a sample. Such prediction maps facilitate direct visual interpretation of model performance , and performance indicators can be extracted from them. These maps can be used...

Computer vision systems have become typical tools of increasing importance to control manufacturing processes and product quality in a non-destructive manner in food industrial processing. During the past several years, we have heard about how hyperspectral imaging, joined with chemometrics, could offer a set of possibilities that may help to incre...

Hyperspectral reflectance imaging in the NIR wavelength range combined with chemometrics shows much promise for detection and identification of foreign bodies among food grains. This method is particularly well suited to the identification of plastic and rubber foreign bodies, since these materials exhibit characteristic absorbances in the near inf...

Aquaphotomics is a new discipline that provides a framework for understanding changes in the structure of water caused by various perturbations, such as variations in temperature or the addition of solutes, using near infrared spectroscopy (NIRS). One of the main purposes of aquaphotomics is to identify water bands as main coordinates of future abs...