Artificial enzyme-based catalytic sensor for the electrochemical detection of 5-hydroxyindole-3-acetic acid tumor marker in urine

作者：Antuna jimenez Daniel; Carmen Blanco Lopez Maria; Jose Miranda Ordieres Arturo; Jesus Lobo Castanon Maria

来源：Sensors and Actuators B: Chemical , 2015, 220: 688-694.

DOI：10.1016/j.snb.2015.05.109

• Artificial enzyme
• Molecularly imprinted catalytic polymer
• Peroxidase-like catalyst
• Core-shell magnetic particles
• Electrochemical sensor

A novel approach towards the development of biomimetic electrochemical sensors is presented. It is based on magnetic-core/porous-shell molecularly imprinted composites as recognition phase. The selected substrate is 5-hydroxyindole-3-acetic acid (5-HIAA), an urinary metabolite used as carcinoid tumor maker. Using 5-HIAA as template molecule, hemin, 4-vinylpyridine and ethylenglycoldimethacrylate crosslinker are polymerized onto the magnetic core to obtain an artificial enzyme with peroxidase activity. An aliquot of a suspension of the resulting material is deposited onto a carbon screen printed electrode, and the solid material is fixed with a permanent magnet to prepare the sensor. The product of the catalytic oxidation of 5-HIAA at the sensing phase is monitored by differential pulse voltammetry. This sensor allows the detection of 5-HIAA with good sensitivity (0.72 +/- 0.01 nA mu M-1) and linear response over a concentration range covering the whole window of normal and pathologic urinary levels of 5-HIAA 1-50 mu M (0.2-9.6 ppm) with a detection limit of 1.4 mu M (0.27 ppm). Urine samples of healthy individuals, spiked with known concentrations of 5-HIAA, yield good recovery values and reproducibility for normal and pathological concentrations (90-100% recovery values, with RSD below 10%).

• 出版日期2015-12-1