title: Fabrication of novel coated pyrolytic graphite electrodes for the selective nano-level monitoring of Cd²⁺ ions in biological and environmental samples using polymeric membrane of newly synthesized macrocycle.
abstract: Novel 5-amino-1,3,4-thiadiazole-2-thiol unit based macrocyclic ionophore 5,11,17-trithia-1,3,7,9,13,15,19,20,21-nonaazatetracyclo[14.2.1.1(4,7).1(10,13)]henicosa-4(20),10(21),16(19)-triene-6,12,18-trithione (M1), was synthesized and characterized. Preliminary studies on M1 have showed that it has more the affinity toward Cd(2+) ion. Thus, the macrocyclic ionophore (M1) was used as electroactive material in the fabrication of PVC-membrane electrodes such as polymeric membrane electrode (PME), coated graphite electrode (CGE) and coated pyrolytic graphite electrode (CPGE) were prepared and its performance characteristic were compared with. The electroanalytical studies performed on PME, CGE and CPGE revealed that CPGE having membrane composition M1:PVC:1-CN:NaTPB in the ratio of 7:37:54:2 exhibits the best potentiometric characteristics in terms of detection limit of 7.58×10(-9) mol L(-1), Nernstian slope of 29.6 mV decade(-1) of activity. The sensor was found to be independent of pH in the range 2.5-8.5. The sensor showed a fast response time of 10s and could be used over a period of 4 months without any significant divergence in its potentiometric characteristics. The sensor has been employed for monitoring of the Cd(2+) ion in real samples and also used as an indicator electrode in the potentiometric titration of Cd(2+) ion with EDTA.
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: Manoj Kumar
authors: MK
authors: Sahani
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India. Electronic address: akscyfcy@iitr.ernet.in.
authors: A K
authors: AK
authors: Singh
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: A K
authors: AK
authors: Jain
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: Anjali
authors: A
authors: Upadhyay
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: Amit
authors: A
authors: Kumar
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: Udai P
authors: UP
authors: Singh
authors: Department of Chemistry, Indian Institute of Technology-Roorkee, Rookee 247667, India.
authors: Shikha
authors: S
authors: Narang
mesh_terms: D002104:Cadmium / Q000032:analysis*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D007477:Ions / Q000032:analysis; D047028:Macrocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D011199:Potentiometry
chemical_list: D007477:Ions; D047028:Macrocyclic Compounds; D011108:Polymers; D002104:Cadmium; D006108:Graphite
keywords: Cd(II) ion-selective sensor; Coated pyrolytic graphite electrode; Macrocycle; Potentiometry; Single crystal X-ray diffraction