Novel biocompatible amide phthalocyanine for simultaneous electrochemical detection of adenine and guanine

Biomolecules like adenine and guanine are important nucleic bases present in DNA and RNA molecules and have significant role in the human body for healthy growth and development. Their alteration and deficiency in their concentration lead to malfunction and abnormal growth and hence, these molecules need to be monitored continuously. Here, copper tetracarboxylic acid phthalocyanine (CuIITCAPc) is synthesized and converted to novel amide linkage 4-(pyridine-3-yl)-4,5-dihydro-1,3-thiazol- copper phthalocyanine (CuIITPTAPc). Synthesized macrocycles are characterized by various physico-analytical techniques which inferred that the synthesized complexes are pure. CuIITPTAPc film was administered on glassy carbon electrode (GCE) and used for the simultaneous determination and monitoring of biologically important adenine (A) and guanine (G) bio-molecules. The GCE/CuIITPTAPc showed significantly better voltammetric response for the simultaneous detection of guanine and adenine in the quantitative range 5 to 35 μM. Differential pulse voltammetry (DPV) using CuIITPTAPc electrode exhibited linear response in the quantitative range 5 to 70 µM with limit of detection (LOD) 1.42 μM for simultaneous detection of guanine and adenine. The chronoamperometric (CA) method displayed linear response in the range 2 to18 and 3 to 27 µM with LOD of 0.66 μM and 1.00 μM for G and A, respectively. The molecules which co-exist with G and A did not respond during CA analysis inferring superior selectivity of the proposed sensor for nucleic acid bases. The designed electrode satisfactorily employed for the real sample analysis.