Highly sensitive determination of paracetamol，uric acid，dopamine and catechol based on flexible plastic electrochemical sensors

Jiabao Zuo, Yuliang Shen, Juanjuan Gao, Haiou Song, Zhiwen Ye, Ying Liang, Shupeng Zhang

ABSTRACT

Flexible sensing is an alternative to traditional sensing and possesses good flexibility and wearability. Intrinsically conductive polymers, particularly poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), have received significant attention due to their high mechanical flexibility and good biocompatibility. Here, we report the design of highly conductive and electrochemically active PEDOT:PSS-coated plastic substrate electrodes by combining N-doped graphene (NG) or S-doped graphene (SG) with methanesulfonic acid-treated PEDOT: PSS (denoted as NG-f-MSA-PEDOT:PSS/PET and SG-f-MSA-PEDOT:PSS/PET) by a simple drop-coating method. At room temperature, the NG-f-MSA-PEDOT:PSS/PET electrode demonstrated the lowest detection limits of 17.09, 33.84, 28.30 and 44.96 nM for paracetamol，uric acid，dopamine and catechol (S/N = 3), respectively. The NG-f-MSA-PEDOT:PSS/PET electrode had good anti-interference ability and reproducibility without employing expensive noble metals and consuming much efforts for polishing the surface of traditional glass carbon electrodes. Most importantly, this film electrode could maintain a stable electrochemical response under different bending and crease states and had excellent mechanical stability and flexibility.

Keywords: N-doped graphene, S-doped graphene, PEDOT: PSS, Electrochemical sensor

In summary, a novel electrochemical sensor based on NG-f-MSA-PEDOT:PSS/PET flexible film electrodes was presented in this work. The conductivity of the flexible film sensor was enhanced by acid treatment without influencing the flexibility and completeness of the PET substrates. A novel electrochemical sensor based on a NG-f-MSA-PEDOT:PSS/PET flexible film electrode was successfully used for PC detection. A series of electrochemical tests indicated the flexible film sensor exhibited excellent electrochemical properties towards PC detection including fast response, wide detection range and low detection limit. Furthermore, the NG-f-MSA-PEDOT:PSS/PET flexible film sensor showed excellent potential in the practical detection of PC as it had a strong anti-interference ability, good reproducibility and long-term stability. Finally, the excellent flexibility of NG-f-MSA-PEDOT:PSS/PET suggested its potential application in wearable electrochemical sensors. This sensor is envisioned to become a wearable device in the future for, as an example, noninvasive monitoring through the loss of micronutrients in sweating fluid, comprising features of lightweight, reduce infection and the easy fabrication required for such applications.