An electrochemically active device is provided for collecting and retaining a blood sample with at least a two-electrode member connected to conductive tracks. A receptor with an integral receptor-membrane arranged on the two-electrode member, to receive non-electrochemically active heamoglobin bioanalyte and its complexes from red blood cells (RBC) of said blood sample, through a lysing agent and convert the non-electrochemically active heamoglobin bioanalyte and its complexes, into an electrochemically active bioanalyte and its electrochemically active complexes. The present invention also provides a point-of-care biosensor incorporated with the device of the present invention and method of measuring for the detection and quantitative measurement of concentrations of haemoglobin (Hb), glycated haemoglobin (GHb), methaemoglobin (MetHb) and myoglobin, in reduced volumes of blood samples, by determining redox current values in the reduced volumes of blood samples.