In the offered study, a biosensor using a novel nano-matrix consisted of the human serum albumin (HSA) and the Pd-doped CdTe quantum dots (Pd:CdTe) and sub-layer multiwall carbon nanotubes (MWCNT) was constructed. The biosensor was employed in rapid sensing of the chlorpyrifos (CPS) pesticide by a single frequency impedance (SFI) strategy. This biosensor response was based on the connections of the CPS to tryptophan residue located at position 214 of HSA content of matrix on the electrode. Biosensor response signals were recorded through impedance |Z| in different individual frequencies using the [Fe(CN)6]3−/4− probe as a connection index. The electron transfer resistance (Rct) of the biosensor was altered linearly by logarithm CPS concentration from 0.5 pM to 500 nM under the optimal conditions with a detection limit of 0.16 pM. The proposed presented biosensor exhibited high sensitivity, wide linear response, excellent reproducibility and stability. As a result, the proposed biosensor will be a promising candidate for screening trace amounts of CPS in the soil and water samples.
