Table 6.

Electrochemical characteristics of other carbon-based electrodes as sensors for caffeine determination.

Medium	Electrohemical Sensor	Method	LOD	CV Oxidation Peaks	Linear Range	Real Sample	References
0.5 M H2SO4	GrRAC GrRGC	DPV	2.9 µM 6.1 µM	/	5–1000 μM	Soft drinks and pharmaceutical formulations	[93]
0.5 M H2SO4	GrRAC GrRGC	CV DPV	2.31 µM 6.33 µM	+1.54 V	0–50 μM	Pharmaceutical formulations and synthetic urine	[92]
0.5 M H2SO4	GrRAC-50% GrRAC-70%	CV, DPV	2.94 μM for GrRAC-70%	+1.51 V for both sensors	2.5–1000 μM	Pharmaceutical formulations and beverages	[91]
0.1 M PBS pH 6	MWCNT-AuNP-CCE	CV DPV	0.354 µM	+0.1 V (DPV)	10–1500 µM	Human serum and urine	[97]
0.1 M PBS pH 7.4	AgNPs:ErGO/PG	CV, SWV	0.54 nM	+1.275 V **	0.001–200 μM	Human urine and serum samples	[99]
0.1 M acetate buffer pH 3	TX-100-MWCNTs/Au	DPV	0.08 µM	+1.45 V (DPV)	0.58–11.50 µM	Tea samples	[98]

**—simultaneously.