Bhera Ram you can do it using an electrocatalytic sensor for the electro-reduction reaction with a pulse technique like square wave voltammetry or differential pulse voltammetry. Regards!
you can use other voltammetry methods i.e. DPV. However, if you want other electrochemical techniques you can use Chronoamperometry or EIS (eventhogh it's a little bit complicated).
If you have only detect the heavy metal ions you can use cyclic voltammetry. But if you want to quantify as well then anodic stripping voltammetry is the best option!