<p>Parkinson’s disease (PD) is a progressive neurological disorder that affects individuals worldwide. One of the most distressing aspects of this condition is the inability to use one’s limbs effectively, despite their physical presence. By the time symptoms become clinically evident, approximately 10–15&#xa0;years have elapsed, during which significant and irreversible neurodegeneration has already occurred. Emerging research characterizes PD as a multifactorial disorder involving complex and interconnected biological pathways, making single-biomarker approaches insufficient for comprehensive detection. Consequently, there is a critical need to develop advanced biosensors capable of simultaneously detecting multiple biomarkers. However, challenges such as biomarker heterogeneity, variability in expression levels, and limited clinical validation continue to hinder the development of robust diagnostic strategies. In this context, optical biosensors have gained prominence due to their exceptional sensitivity, label-free detection capabilities, rapid response times, and compatibility with diverse PD biomarkers. Technologies such as surface plasmon resonance, Raman and surface-enhanced Raman spectroscopy (SERS), and optical fibre-based sensors offer powerful avenues for real-time quantification of α-synuclein proteoforms, inflammatory mediators, and PD-associated nucleic acids. Despite these advantages, issues related to sensor reproducibility, lack of standardization, and challenges in large-scale implementation remain significant barriers, which are critically examined in this article. It also highlights the role of established and emerging biomarkers in PD pathophysiology and explores how optical biosensing technologies provide sensitive, specific, and minimally invasive platforms for early detection. Furthermore, we discuss future prospects, including the development of multiplexed detection systems, integration with microfluidics and wearable technologies.</p> Graphical abstract <p></p>