6th Edition of Neurology World Conference 2026

Abstract

Monitoring cortisol concentration as a stress biomarker indicates physiological states for prognosis and diagnosis aims. Cortisol incorporates into many physiological mechanisms like immune function, neural development, sleeping, learning and memory, cell death, metabolism and fat distribution, reproduction and ageing. In response to psychological and physical stresses, a higher cortisol secretion triggers several physiological mechanisms for coping with stress successfully. Nevertheless, long-time secretion can cause different health issues, leading to morbidity and mortality. In Cushing’s syndrome, due to repeated increases in cortisol amount, a series of symptoms, such as anxiety, severe fatigue, obesity, depression, cardiovascular disease, and cognitive difficulties, appear.

Conversely, Insufficiency in cortisol quantity is the main cause of Addison’s disease. Low blood sugar (hypoglycemia), low blood pressure, faintness, hyperpigmentation, weight loss, salt craving, nausea, vomiting, and diarrhea (gastrointestinal symptoms) are the symptoms of Addison’s disease. The serum contains a protein‐bound cortisol fraction, which is physiologically inactive. The salivary free-cortisol passes through the acinar cells by passive diffusion and correlates to Adrenocorticotrophin hormones. The salivary cortisol measurement has some advantages over serum cortisol quantification, such as non-invasive sampling, the possibility of home collection, and measurement without contamination of results by needle stress. Real-time cortisol quantification can be obtained by saliva compared to urine, accumulating in the bladder for a few hours.

The saliva sample collected from healthy females at 8:30 am, due to cortisol secretion rhythm. Graduate students at the age of 29 were selected. The average of three repeats of measurement was reported. Nanobiosensor incubated with a saliva sample (100 μl) for 30 minutes in room tempreature. The fluorescence emmission measured in 524 nm. Samples examined by Elisa kit and TISS nanobiosensor for validating the performance efficiency of the presented nanobiosensor. The results achieved by TISS nanobiosensor were compared and showed less than one nmol variation which revealed the reliability of this TISS nanobiosensor.

This nano biosensor utilizes TISS, AIE, and SAIE mechanisms. This unique multimer structure serves both as a biorecognition and transducer component. When cortisol is present, the aptamer undergoes a conformational change, resulting in close positioning of the tails, leading to AIE phenomena.