Table 2.

Voltammetric detection of codeine reported at various electrodes.

Electrode	Linear range	Detection limit	Reference
CME	0–32 µM	10 nM	[17]
CMSPE	2.5–45 µM	20 nM	[18]
PB/Pd/Al	2–30 µM	0.8 µM	[19]
Pd/Al	0.1–3 mM	5 µM	[20]
Boron-doped diamond	0.1–60 µM	80 nM	[22]
SWCNTs/CCE	0.2–230 µM	0.11 µM	[23]
Nafion/MWCNTs (t acc = 120 s)	0–0.5 µM	14 nM	This work