Pattern recognition of neurotransmitters using multimode sensing

•Multimode microsensors based on diamond paste and different porphyrines were used for the pattern recognition of dopamine, epinephrine and norepinephrine.•Stochastic and differential pulse voltammetry modes were used.•Dopamine, epinephrine and norepinephrine were determined from whole blood and urine samples.•The microsensor of choice was the one based on protoporphyrin IX. Pattern recognition is essential in chemical analysis of biological fluids. Reliable and sensitive methods for neurotransmitters analysis are needed. Therefore, we developed for pattern recognition of neurotransmitters: dopamine, epinephrine, norepinephrine a method based on multimode sensing. Multimode sensing was performed using microsensors based on diamond paste modified with 5,10,15,20-tetraphenyl-21H,23H-porphyrine, hemin and protoporphyrin IX in stochastic and differential pulse voltammetry modes. Optimized working conditions: phosphate buffer solution of pH 3.01 and KCl 0.1mol/L (as electrolyte support), were determined using cyclic voltammetry and used in all measurements. The lowest limits of quantification were: 10−10mol/L for dopamine and epinephrine, and 10−11mol/L for norepinephrine. The multimode microsensors were selective over ascorbic and uric acids and the method facilitated reliable assay of neurotransmitters in urine samples, and therefore, the pattern recognition showed high reliability (RSD