A Review of Laser-Induced Breakdown Spectroscopy (LIBS) for Document Examination: Fundamentals, Mechanism, and Application

Document examination is one of the main types of investigations in forensic science, particularly in cases involving questioned documents. These documents include assorted forms of written or printed texts on different substrates (paper, banknotes, etc.) with uncertain authenticity. Ink analysis plays a vital role in document examination. It is often focused on understanding the chemical composition of the ink, which can be colorants, solvents, vehicles, and additives. Document examiners utilize several analytical tools including laser-induced breakdown spectroscopy (LIBS). The use of this instrument has gained prominence for its ability to detect multiple elements, offer straightforward sample preparation, minimize sample destruction, and provide fast and accurate readings. This paper reviews previous research that employed LIBS for document examination, highlighting its modern applications and approaches in analysing various types of documents. Furthermore, this paper discusses the strengths and weaknesses of this instrument as a viable technique in the field of document examination.