Novel imidazole PVC-based sensor based on a thiopyrilium compound

Area of Science:

• Electroanalytical Chemistry
• Chemical Sensors
• Materials Science

Background:

• Imidazole is a crucial biological molecule with diverse applications.
• Accurate detection of imidazole is essential in various fields, including clinical diagnostics.
• Existing detection methods may suffer from limitations in sensitivity, selectivity, or interference.

Purpose of the Study:

• To develop and characterize a novel membrane sensor for imidazole detection.
• To evaluate the sensor's performance in terms of sensitivity, detection limit, and response time.
• To assess the sensor's applicability in real-world samples, such as synthetic serum.

Main Methods:

• Fabrication of an ion-selective electrode (ISE) using poly(vinyl chloride) (PVC) matrix.
• Incorporation of 2,4,6-triphenyl thiopyrilium perchlorate (TTP) as a charged carrier.
• Optimization of sensor composition with dibutyl phthalate (DBP) and oleic acid.
• Potentiometric measurements to determine imidazole concentration over a wide range.
• Evaluation of selectivity against common interfering species and application in synthetic serum.

Main Results:

• The developed sensor exhibits a linear response to imidazole over a concentration range of 1.0 x 10(-5) to 1.0 x 10(-1) M.
• A favorable Nernstian slope of +33.5 +/- 0.5 mV per decade was achieved.
• The sensor demonstrates a low detection limit of 3.0 x 10(-6) M.
• High sensitivity allows detection of imidazole as low as 0.2 microg/ml with negligible interference from amino acids and other components.
• The electrode shows good operational stability for at least four weeks and a fast response time (<30 s).
• Successful determination of imidazole in synthetic serum samples validates the sensor's practical utility.

Conclusions:

• A novel and highly sensitive imidazole membrane sensor based on TTP has been successfully developed.
• The sensor offers excellent potentiometric performance, including a wide linear range, low detection limit, and good selectivity.
• The proposed sensor provides a reliable and efficient method for imidazole determination in complex matrices like synthetic serum.