Poly-taurine/poly-L-glutamic acid double-layer coating as potential candidates for surface modification of carbon felt electrode for discrimination and simultaneous detection of morphine and tramadol.

An ultrasensitive and reliable electrochemical scaffold was designed for the individual and simultaneous measurement of morphine (Mor) and tramadol (Trm) addictive and illegal drugs, utilizing a cost-effective and flexible carbon felt electrode modified with double-layer poly-taurine/poly-L-glutamic acid (P(Tau)/P(Glu)/CF). It is worth noting that drugs have now become a part of daily life in all societies, and the consumption of tranquilizers and opiates such as Mor and Trm has also increased. Given the frequent co-use of Mor and Trm, accurate and reliable methods for their simultaneous measurement are crucial. Simultaneous diagnostics make the determination more efficient and cost-effective by reducing the need for multiple sensors. Surface modification of CFE was carried out by a green approach, facile and straightforward route by layer-by-layer electropolymerization, forming a thin polymeric film with abundant functional groups responsible for anchoring narcotic drugs. The P(Tau)/P(Glu)/CFE composite showed an exceptionally high rate of active site exposure and proper electrochemical activity, attributed to the synergistic effects of the constituent materials. P(Tau)/P(Glu)/CFE was successfully used to detect saliva, urine, plasma, and body sweat samples with satisfactory recoveries.