Fig. 1From: Graphene oxide modified screen-printed electrode for highly sensitive and selective electrochemical detection of ciprofloxacin residues in milkEffect of Mn2+ on CIP determination. A Determination of CIP in the absence of Mn2+; B before and after adding 10 μM Mn2+; C differential pulse stripping voltammetry curves of CIP at concentration of 0–20 μM; D a larger version of CBack to article page