Theoretical Investigation of Single‐Atoms Encapsulated by Fullerenes (C59X: X=As, Ga, Ge) as Biosensors For Uric Acid (UA)

Abstract

This work focuses on comparative investigation of three different doped surfaces on a nano‐cage C59As, C59Ga and C59Ge to understand their sensitivity and ability to adsorbed uric acid (UA). This is done using the density functional theory (DFT) computation, employing ωB97XD/def2SVP level of theory. After interaction of the surfaces with UA, FMO results reveal that UA@C59As is more reactive with Eg=5.1911 eV and UA@C59Ga is more stable with Eg=5.3304 eV, while UA@C59Ge is relatively reactive and relatively stable with Eg=5.2145 eV. Geometric optimization analysis reveals that UA@C59Ge shows the best interaction with the least adsorption distance (1.9437 Å) and UA@C59Ga shows a relatively good interaction with adsorption distance (1.9674 Å) while UA@C59As reveal the poorest interaction with adsorption distance of (3.6370 Å). The calculated thermodynamic parameters deduced that UA@C59Ga is more stable compared to UA@C59As and UA@C59Ge complexes, due to the fact that the calculated values of ℇ°+ℇZPE, ℇ°+Gcorr, ℇ°+Hcorr and ℇ°+Etot are less negative in compound UA@C59Ga. Negative Eads values of UA@C59As (−0.5968 eV), UA@C59Ga (−1.8798 eV) and UA@C59Ge (−1.1656 eV) were observed from adsorption studies and its sensor mechanism implying an enhanced chemical adsorption was manifested and this indicates the presence of a covalent interaction. Similarly, the result of interaction energy (Eint) reveal UA@C59Ge to have an Eint of 22.3978 eV greater than UA@C59Ga (21.5832 eV) and far greater than UA@C59As (2.4593 eV) there by confirming UA@C59Ga and UA@C59Ge to be strongly interacted. However, all analysis in this work has shown that C59Ge is the best promising biomarker candidate for adsorbing UA, although C59Ga has also demonstrated a good UA adsorption candidate.