Development of non-invasive biochemical device for monitoring the lithium level from saliva for bipolar disorder patients

This research aims at developing low cost portable proactive healthcare technologies to put more control into the hands of patients especially who have mental illness so that the earliest signs of health problems with medications can be detected and corrected. Monitoring prescription drugs such as lithium, clozapine etc is important for safe guarding the well-being of the bipolar sufferers. Therapeutically useful amounts of lithium (~ 0.6 to 1.2 mmol/L) are only slightly lower than toxic amounts (>;1.5 mmol/L), so the concentration of lithium must be carefully monitored during treatment to avoid toxicity. A very sensitive analytical method was proposed for the spectrofluorimetric determination of lithium base on its reaction with 1,4-dihydroxyanthraquinone (Quinizarin). The fluorescence is measured at an excitation wavelength of 590 nm and emission wavelength of 620 nm. Saliva sample was tested using the proposed portable device in order to validate the feasibility of saliva as a sample to detect lithium ions. Calibration results presented that linear range of detection was 0.25 mM ~ 6.0 mM of Li⁺ in saliva with R²=0.99. The range of detection covers sufficiently the therapeutic range of lithium drugs.