High selectivity for sodium dodecyl sulphate by polymer nanoparticles and detection of proteins based on the polymer nanoparticles-sodium dodecyl sulphate system

A fluorescence assay for the sensitive determination of sodium dodecyl sulfate (SDS) based on polymer nanoparticles (PNPs) prepared by polyethyleneimine (PEI) and ascorbic acid (AA) is developed. SDS reacts with PNPs to form amide by aminolysis ester reaction, resulting in a strong fluorescence enhancement of PNPs. Notably, sodium dodecylbenzenesulphonate (SDBS) and sodium dodecyl sulfonate (SDSO) cannot interact with PNPs, so this way exhibits a special selectivity to SDS in the presence of SDBS and SDSO. Under the optimum conditions, this fluorescent nanosensor shows the linear range of SDS from 0.144 to 2.016 mu g mL(-1) and the limit of detection is 0.051 mu g mL(-1). Besides, on the basis of the reaction between SDS and proteins, the fluorescence of PNPs-SDS system quenches in the presence of biologically-relevant levels of myoglobin and thrombin, and displays good sensitivity and selectivity. (C) 2017 Elsevier B.V. All rights reserved.