We successfully designed and prepared a g-C3N4-ZnS-DNA nanocomposite by a simple method and systematically investigated its morphology,microstructure,and electrocatalytic properties.The as-prepared g-C3N4-ZnS-DNA nanocomposite possessed the electrocatalytic activity of g-C3N4-ZnS and the conductivity of DNA.The presence of DNA was found to enhance the electrocatalytic response of the nanocomposite towards environmental hormones,e.g.pentachlorophenol and nonylphenol,owing to the interaction between g-C3N4-ZnS and DNA,indicating that a stable nanocomposite was formed.The three components showed synergistic effects during electrocatalysis.Electrochemical impedance spectra indicated that the g-C3N4-ZnS-DNA nanocomposite dramatically facilitated the electron transfer of a modified electrode.The co-doping of g-C3N4 film with ZnS and DNA doubled the electrochemical response of the modified electrode in comparison with that of unmodified g-C3N4 film.The detection limits（3 S/N） of pentachlorophenol and nonylphenol were3.3×10^-9 mol L^-1.Meanwhile,we propose a possible Z-scheme mechanism for electron transfer in the g-C3N4-ZnS-DNA nanocomposite and the possible pentachlorophenol and nonylphenol electrocatalytic oxidation mechanism.The g-C3N4-ZnS-DNA nanocomposite-modified electrode was demonstrated to be effective for electrochemical sensing of trace environmental hormones in water samples.
