Conjugation of Bovine Serum Albumin With ZnO Nanosphere-A Novel Approach for Ultra-Low Level Mercury Ion Detection

Solution-processed bovine serum albumin conjugated with ZnO nanosphere (BCZ) have been synthesized for ultra-low level mercury ion detection. Simple drop casting technique was adopted to fabricate such a mercury ion (Hg
²⁺
) detection scheme. Morphological and optical characterization of the BCZ was performed by Transmission Electron Microscopy (TEM), UV-Vis and Fluorescence spectroscopic technique prior to device fabrication. The working principle of the BCZ device for Hg
²⁺
detection depends upon the variation of conductance with various concentration of Hg
²⁺
. An extensive study was carried out to investigate the effect of Hg
²⁺
upon transport properties of BCZ. The ultra-low level of Hg
²⁺
sensing was performed using this electrical detection technique. More importantly, this proposed BCZ based detection technique is found to be simple, inexpensive and very fast in responding (response time ~ 2.5 s to heavy metal ion with a limit of detection (LOD) 0.03 fg/ml (S/N> 3).