Ultralow fouling electrochemical detection of uric acid directly in serum based on phase-transited bovine serum albumin and conducting polymer

Electrochemistry with antifouling sensing interfaces that effectively resist the adsorption of nonspecific biomolecules provides a powerful mean for the accurate and sensitive detection of disease biomarkers in complex biofluids. However, there are few strategies to acquire a stable and solid antifouling coating on any substrate by a simple way. Herein, a simple one-step assembly method has been adopted to construct phase-transited bovine serum albumin (PTB) antifouling layers. Prior to construction of the antifouling layers, the poly(3,4-ethylenedioxythiophene) (PEDOT) doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (ionic liquid, IL) were firstly electrodeposited on bare electrodes, endowing good conductivity and catalytic capability for the developed sensor. Subsequently, with the assist of tris(2-carboxyethyl)phosphine (TCEP), the disulfide bonds of bovine serum albumin (BSA) were reduced to form PTB, which can be coated on the PEDOT-IL modified electrode to construct an antifouling electrochemical senor (PTB/PEDOT-IL/GCE) for the detection of uric acid (UA) in human serum. The UA sensor demonstrated a good linear range from 1.11 µmol/L to 798.9 µmol/L, with a high sensitivity of 0.556 µA µmol L−1 cm−2. The combination of conducting polymers with one-step assembly of PTB offers a universal and reliable method for the modification of various electrodes to determine target molecules in complex human body fluids.