A Laser Induced Breakdown Spectroscopy (LIBS) technique has been applied for the identification of four widely used plastics, polyethylene terephthalate (PET), high-density polyethylene (PE), polypropylene (PP) and polystyrene (PS), whose recycling is required from commercial and biosafety points of view. The 3rd harmonic (355 nm) nanosecond pulse from an Nd:YAG laser is used to create plasma on the sample surface and identification of the type of the plastic is derived from the plasma emission. Principal Component Analysis (PCA) of the LIBS spectra is employed for the classification of plastics. Distinct methods have been used, apart from principal components of PCA, to further confirm our results. Statistical parameters, viz., Mahalanobis distance (M-distance) and spectral residuals were used for decisive match/no match test which provided successful classification of plastics. Receiver Operating Characteristic (ROC) and Youden's index analyses were carried out to obtain the diagnostic threshold for classification of all four classes of plastics. Sensitivity, specificity, predictive values and discriminative accuracy of the classification tests based on the optimum threshold were calculated. This proves the analytical predictive capabilities of the LIBS technique for plastic identification and classification. The technique of LIBS, in future, can be routinely used in field applications such as plastic waste sorting and recycling.

In recent years, the application of lasers for modifying the surface topography of dental biomaterials has received increased attention. This review paper aims to provide an overview of the current status on the utilization of lasers as a potential tool for surface modification of dental biomaterials such as implants, ceramics, and other materials used for restorative purposes. A literature search was done for articles related to the use of lasers for surface modification of dental biomaterials in English language published between October 2000 and March 2023 in Scopus, Pubmed and web of science, and relevant articles were reviewed.

This review discusses the importance of hyphenating different laser-based techniques such as Laser-Induced Breakdown Spectroscopy (LIBS), Raman spectroscopy and Laser-Induced Fluorescence spectroscopy (LIF) and the applications of the hybrid systems. These spectroscopic techniques, in single and multi-modes, are widely accepted as an efficient tool to retrieve information from atomic and molecular systems such as knowledge on chemical bonds, molecular structure and geometry, interactions and related mechanisms etc. Analytical capabilities of such systems which combine LIBS, Raman, and LIF are highly desirable since one can acquire complementary information from the same sample enabling a remarkable potential for various applications in diverse fields like archeology, mineralogy, planetary explorations, clinical chemistry, biomedical and environmental monitoring etc to extract more information. In this review, attention has been devoted to the works of combined LIBS-LIF-Raman technique in different fields and its significance, along with brief discussions on other combinations like LIBS-Raman, LIBS-LIF, and Raman-LIF.