A novel electrochemical biosensor for ultrasensitive detection of serum total bile acids based on enzymatic reaction combined with the double oxidation circular amplification strategy

作者：Tian, Gang; Ding, Min; Xu, Biao; He, Yifan; Lyu, Wenjing; Jin, Mingchao; Zhang, Xiaoqing^*

来源：Biosensors and Bioelectronics, 2018, 118: 31-35.

DOI：10.1016/j.bios.2018.07.030

• Bile acid
• Reduced nicotinamide adenine dinucleotide
• Tris(bipyridine)-ruthenium (II)
• Screen printed carbon electrode
• Serum

Serum total bile acids (TBA) level is used as a sensitive and reliable index for hepatobiliary diseases in clinics. Herein, a novel electrochemical biosensor was fabricated using enzymatic reaction coupling with the double oxidation circular amplification strategy for the detection of human serum TBA. With the catalysis of 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD), 3 alpha-bile acids reacted specifically with nicotinamide adenine dinucleotide (NAD(+)). And then, the reduced nicotinamide adenine dinucleotide (NADH) was produced. After that, the NADH reacted with the electron mediator of tris(2,2'-bipyridine) ruthenium(III) (Ru(bpy)(3)(3+)), which was then transformed to Ru(bpy)(3)(2+). Ultimately, Ru(bpy)(3)(2+) was further oxidized to Ru(bpy)(3)(3+) under a certain voltage, which was detected by the chronoamperometry assay. The detection was performed using a disposable unmodified screen-printed carbon electrode (SPCE) without sample preparation. The proposed biosensor showed high sensitivity and accuracy with the linear range from 5.0 to 150.0 pmol/L in 10(6)-fold dilution serum. The established method had a good correlation with the enzymatic cycling method (r = 0.9372, P < 0.001, n = 72) commonly used in clinic. The electrochemical biosensor is simple, ultrasensitive and without sample pretreatment, showing great potential for point-of-care testing (POCT) of serum TBA in clinical samples. In addition, the biosensor is cost-effective with a small volume of samples, especially suitable for those who have difficulties in blood collection, such as infants, children and some small animals.

• 出版日期2018-10-30
• 单位重庆医科大学