Carbon nanotubes based electrochemical aptasensing platform for the detection of hydroxylated polychlorinated biphenyl in human blood serum

• Published in: Biosensors & bioelectronics 2014-04, Vol.54, p.78-84
• Main Authors: Pilehvar, Sanaz, Ahmad Rather, Jahangir, Dardenne, Freddy, Robbens, Johan, Blust, Ronny, De Wael, Karolien
• Format: Article
• Language: English
• Subjects: Aptamers, Nucleotide - chemistry; Biological and medical sciences; Biosensing Techniques - instrumentation; Biotechnology; Dielectric Spectroscopy; Electrochemical aptasensor (APT-MWCNT/GCE); Electrochemical Techniques; Electrodes; Fundamental and applied biological sciences. Psychology; Humans; Hydroxylated PCB (OH-PCBs); Hydroxylation; Limit of Detection; Microscopy, Atomic Force; Multi-walled carbon nanotubes (MWCNTs); Nanotubes, Carbon - chemistry; Polychlorinated Biphenyls - blood; Serum analysis
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2013.10.018

A novel strategy to sense target molecules in human blood serum is achieved by immobilizing aptamers (APTs) on multi-walled carbon nanotubes (MWCNT) modified electrodes. In this work, the aminated aptamer selected for hydroxylated polychlorinated biphenyl (OH-PCB) was covalently immobilized on the surface of the MWCNT-COOH modified glassy carbon electrode through amide linkage. The aptamers function as recognition probes for OH-PCB by the binding induced folding of the aptamer. The developed aptasensing device was characterized by electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR). The aptasensor displayed excellent performance for OH-PCB detection with a linear range from 0.16 to 7.5μM. The sensitivity of the developed aptasensing platform is improved (1×10−8M) compared to the published report (1×10−6M) for the determination of OH-PCB (Turner et al., 2007). The better performance of the sensor is due to the unique platform, i.e. the presence of APTs onto electrodes and the combination with nanomaterials. The aptamer density on the electrode surface was estimated by chronocoulometry and was found to be 1.4×1013moleculescm−2. The validity of the method and applicability of the aptasensor was successfully evaluated by the detection of OH-PCB in a blood serum sample. The described approach for aptasensing opens up new perspectives in the field of biomonitoring providing a device with acceptable stability, high sensitivity, good accuracy and precision. •Demonstrating the strength of electrochemistry for aptasensing.•Describing a novel electrochemical aptasensing platform based on the combination of carbon nanotubes and aptamers.•Characterizing the sensing platform by means of spectroscopy and microscopy techniques.•Representing an aptasensing platform for sensitive and selective detection of hydroxylated PCBs.•Unraveling the applicability of the aptasensor towards OH-PCB detection in human blood serum samples.