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People suffered from essential hypertension have increased oxidative stress. Thus, adding vitamin C to their medical therapy resulted in decreasing the oxidative stress and increasing the antioxidant status. This may prevent further vascular damage due to the oxidative stress, leading to a better diagnosis in critical hypertension patients. A novel sensor was fabricated based on NdFeO3 nano‐perovskite/glycine/carbon nanotubes modified carbon paste electrode in presence of sodium dodecyl sulfate; GLNFCNTCP‐SDS for electrochemical sensing and simultaneous determination of antihypertensive and antioxidant drugs, Amlodipine (AML) and ascorbic acid. The developed nanocomposite showed interactive characteristics of all the modifiers as high conductivity, enhanced surface area, surface fouling resistance and stability. This leads to accelerated electron transfer rate and increased current response of electro‐oxidation of AML by 8.3 folds compared to unmodified electrode. The method validity was investigated successfully by the quantitative analysis of AML in human urine samples and Norvasc tablets with acceptable recovery results. The featured merits of the proposed composite in the analysis of AML in human urine samples were; wide concentration range of 0.003 μmol L−1 to 200 μmol L−1, sensitivity of 113.2 μA/μmol L−1, detection limit of 0.704 nmol L−1, and quantification limit of 2.35 nmol L−1. [ABSTRACT FROM AUTHOR]

Graphite/SrPdO3 was utilized for the sensitive determination of some neurotransmitters, namely dopamine (DA), epinephrine (EP), norepinephrine (NE), serotonin (ST), 3,4-dihydroxyphenylacetic acid (DOPAC) and L-dopa. Graphite/SrPdO3 exhibited higher electrocatalytic activity toward the studied neurotransmitters compared to bare graphite. It was confirmed that graphite electrode was more suitable substrate for immobilization of SrPdO3 perovskite compared to other surfaces. Moreover, simultaneous determinations of L-dopa, ascorbic acid (AA) and uric acid (UA) or ST were achieved with large peak potential separation. The linear response for L-dopa was obtained in the range of 0.6 µ mol L-1 to 9 µ mol L-1 with correlation coefficient 0.996 and detection limit 1.63 nmol L-1. The proposed composite sensor exhibited high reproducibility, enhanced sensitivity, selectivity, anti-interference ability, unique long-term stability (over two months) and applicability in the human urine samples with satisfying results. [ABSTRACT FROM AUTHOR]