Biomarker adoption is anticipated to greatly impact disease diagnostics in the years ahead. Biomarkers can assist in considering appropriate tools to predict prognosis and effectively support therapy for cancer patients, since in oncology their applications are vast and have transformed diagnostics and treatments. Furthermore, they can help to provide an in-depth analysis and understanding of mechanisms of action and challenges to treatment. Early and accurate diagnoses, short operation times, and low costs are constant demands, which tend to focus on new optical biosensor technologies. Biosensor technologies are an outstanding tool necessary for quick and stable detection of disease biomarkers, essential for treatment and cures.

Optics and biosensors in disease-related detection applications and biomarker-based early diagnoses methods support reducing mortality rates, but can be challenging to implement because of the lack of sensitivity and specificity. Optical-based biosensor tools for early diagnosis typically require sensitivity, selectivity, linearity, stability, and reproducibility for the rapid acquisition of patient data to obtain efficient clinical decisions. Although emerging biomarkers for early diagnosis of disease are nearly in clinical application, more research needs to be carried out on new biomarkers for analyzing their performance and suitability, since biomarker-based strategies and cutting-edge diagnostic testing are often not efficaciously utilized in medical practice. Diagnosing and analysing the risk of a specific disease is often based on biomarker detection assays which are significant for early diagnosis. Furthermore, optical biosensor-based diagnostic biomarkers can aid in creating a promising future for precise early diagnosis and treatment of many diseases as it plays a key role in the drug development process.

The aim of this Special Issue is to assist the accurate early diagnosis of medical conditions in individuals by reporting on evolving applications, techniques, and strategies based on optics and biosensors with an in-depth analysis of disease biomarkers. Original research and review articles discussing the significance of optical biosensing technologies and new biomarkers in the advanced diagnosis and prediction of diseases are most welcome.

Potential topics include but are not limited to the following:

• Current trends in portable biosensors of biomarkers for preventing and controlling disease spreading
• Applications of biosensors in adopting biomarkers for personalized/precision medicine
• Evolving optical biosensors in accurate detection of biomarkers for diagnosis of brain disorders (eg., parkinson's, alzheimer's, etc.,)
• Optical based biosensor for point-of-care in early diagnosis and cancer biomarker detection
• Challenges of developing biosensor technology for biomarker assessment of early osteoarthritis
• Impacts of recent optical-based biosensor for multiple cardiac biomarkers in early diagnosis
• Optical and wearable nano biosensors for early diagnosis and monitoring of multiple sclerosis
• Advances in optical biosensors enabled ultrasensitive detection of biomarkers for chronic kidney disease
• Optical biosensor and digital biomarker for early diagnosis of the deadly disease and post-surgical critical care
• Recent validation and testing of optical-based biosensors in emerging biomarkers for efficient early diagnosis
• Plasmonic optical biosensor and non-invasive imaging biomarker for early diagnosis, risk, and screening of ocular diseases