Nanodiamonds stabilized in dihexadecyl phosphate film for electrochemical study and quantification of codeine in biological and pharmaceutical samples

Abstract A new architecture for a sensor and a voltammetric procedure were proposed, using a glassy carbon electrode modified with nanodiamonds and dihexadecyl phosphate for determination of codeine (COD) in pharmaceutical and biological fluid samples. Square-wave voltammetry (SWV) was used and the relevant experimental parameters were optimized. Under optimal experimental conditions, the analytical curve presented a linear concentration range from 0.299 to 10.8 μmol L −1 , and a limit of detection of 54.5 nmol L − 1 . The proposed voltammetric method was used for COD determination in commercial pharmaceutical and biological fluid samples such as urine and human serum with satisfactory results.