Topic Review
X-ray Photoelectron Spectroscopy
X-ray photoelectron spectroscopy (XPS) is a qualitative and quantitative chemical analysis technique. It is surface-sensitive due to its limited sampling depth, which confines the analysis only to the outer few top-layers of the material surface. This enables researchers to understand the surface composition of the sample and how the chemistry influences its interaction with the environment. 
  • 551
  • 02 Jul 2022
Topic Review
Vibrational Biospectroscopy for Endometrial Cancer Diagnosis and Screening
Endometrial cancer (EC) is the sixth most common cancer and the fourth leading cause of death among women worldwide. Early detection and treatment are associated with a favourable prognosis and reduction in mortality. Unlike other common cancers, however, screening strategies lack the required sensitivity, specificity and accuracy to be successfully implemented in clinical practice and current diagnostic approaches are invasive, costly and time consuming. Such limitations highlight the unmet need to develop diagnostic and screening alternatives for EC, which should be accurate, rapid, minimally invasive and cost-effective. Vibrational spectroscopic techniques, Mid-Infrared Absorption Spectroscopy and Raman, exploit the atomic vibrational absorption induced by interaction of light and a biological sample, to generate a unique spectral response: a “biochemical fingerprint”. These are non-destructive techniques and, combined with multivariate statistical analysis, have been shown over the last decade to provide discrimination between cancerous and healthy samples, demonstrating a promising role in both cancer screening and diagnosis. 
  • 377
  • 18 May 2022
Topic Review
Vancomycin with Muramyl Pentapeptide
Vancomycin and a native muramyl pentapeptide ended with D-alanine (MPP-D-Ala), and vancomycin and a modified muramyl pentapeptide ended with D-serine (MPP-D-Ser) form complexes in a very specific way. This complexes provide a basis for characterizing the type and stability of the connection. The type of experimentally measured and computer-simulated interactions opens the field for discussion on possible modifications to the structure of vancomycin or muramyl pentapeptide to obtain their desired characteristics.
  • 637
  • 07 Feb 2022
Topic Review
T-MIR Spectroscopy Applications in Coffee and Cocoa
Nowadays, coffee and cocoa have broad applications in the food and pharmaceutical industries due to their organoleptic and nutraceutical properties, which have turned them into products of great commercial demand. Consequently, these products are susceptible to fraud and adulteration, especially those sold at high prices, such as saffron, vanilla, and turmeric. This situation represents a major problem for industries and consumers’ health. Implementing analytical techniques, i.e., Fourier transform mid-infrared (FT-MIR) spectroscopy coupled with multivariate analysis, can ensure the authenticity and quality of these products since these provide unique information on food matrices.
  • 391
  • 01 Mar 2022
Topic Review
Spectroscopy in Plant-Based Foods and Beverages
Near-infrared (NIR) spectroscopy and machine vision systems, such as hyperspectral imaging (HSI), are among the most successful technologies applied for the quality evaluation and safety inspection of several commodities.
  • 144
  • 28 Dec 2023
Topic Review
Spectrophotometric Methods for Measurement of Antioxidant Activity
The antioxidant potential can be measured by various assays with specific mechanisms of action, including hydrogen atom transfer, single electron transfer, and targeted scavenging activities. Understanding the chemistry of mechanisms, advantages, and limitations of the methods is critical for the proper selection of techniques for the valid assessment of antioxidant activity in specific samples or conditions. There are various analytical techniques available for determining the antioxidant activity of biological samples, including food and plant extracts. The different methods are categorized into three main groups, such as spectrometry, chromatography, and electrochemistry techniques. Among these assays, spectrophotometric methods are considered the most common analytical technique for the determination of the antioxidant potential due to their sensitivity, rapidness, low cost, and reproducibility.
  • 712
  • 28 Nov 2022
Topic Review
Signal-Amplifying Substrates for Surface-Enhanced Raman Scattering-Based Bioassays
Surface-enhanced Raman spectroscopy (SERS) has become a powerful detection scheme for many applications, particularly bioassays, due to its unique strengths, such as its ultrasensitive performance. Due to the development of various SERS substrates, more SERS-based bioassays with improved sensitivity and reproducibility have been designed and manufactured. 
  • 142
  • 24 Aug 2023
Topic Review
Random Laser Properties
In a random laser (RL), optical feedback arises from multiple scattering instead of conventional mirrors. RLs generate a laser-like emission, and meanwhile take advantage of a simpler and more flexible laser configuration. The applicability of RLs as light sources and optical sensors has been proved. 
  • 356
  • 13 Jan 2023
Topic Review
Raman Spectroscopy in Biosensing
The effect of Raman scattering is a result of inelastic light scattering processes, which lead to the emission of scattered light with a different frequency associated with molecular vibrations of the identified molecule. Spontaneous Raman scattering is usually weak, resulting in complexities with the separation of weak inelastically scattered light and intense Rayleigh scattering. These limitations have led to the development of various techniques for enhancing Raman scattering, including resonance Raman spectroscopy (RRS) and nonlinear Raman spectroscopy (coherent anti-Stokes Raman spectroscopy and stimulated Raman spectroscopy). Furthermore, the discovery of the phenomenon of enhanced Raman scattering near metallic nanostructures gave impetus to the development of the surface-enhanced Raman spectroscopy (SERS) as well as its combination with resonance Raman spectroscopy and nonlinear Raman spectroscopic techniques. The combination of nonlinear and resonant optical effects with metal substrates or nanoparticles can be used to increase speed, spatial resolution, and signal amplification in Raman spectroscopy, making these techniques promising for the analysis and characterization of biological samples.
  • 453
  • 07 Jan 2022
Topic Review
Raman Spectroscopy for Monitoring of Photopolymerization Systems
Raman spectroscopy provides the flexibility and resolution needed for in-situ and real-time monitoring of a wide variety of photopolymerization systems, as well as characterization of polymers resulting from these inherently fast and energy-efficient reactions.
  • 95
  • 27 Sep 2023
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