Conducting polymer composite-based biosensing materials for the diagnosis of lung cancer: A review.

The development of a simple and fast cancer detection method is crucial since early diagnosis is a key factor in increasing survival rates for lung cancer patients. Among several diagnosis methods, the electrochemical sensor is the most promising one due to its outstanding performance, portability, real-time analysis, robustness, amenability, and cost-effectiveness. Conducting polymer (CP) composites have been frequently used to fabricate a robust sensor device, owing to their excellent physical and electrochemical properties as well as biocompatibility with nontoxic effects on the biological system. This review brings up a brief overview of the importance of electrochemical biosensors for the early detection of lung cancer, with a detailed discussion on the design and development of CP composite materials for biosensor applications. The review covers the electrochemical sensing of numerous lung cancer markers employing composite electrodes based on the conducting polyterthiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, molecularly imprinted polymers, and others. In addition, a hybrid of the electrochemical biosensors and other techniques was highlighted. The outlook was also briefly discussed for the development of CP composite-based electrochemical biosensors for POC diagnostic devices.

Catalytic SrMoO4 nanoparticles and conducting polymer composite sensor for monitoring of K+-induced dopamine release from neuronal cells.

Octahedral SrMoO4 nanoparticles (NPs) with a high degree of crystallinity and controlled size (250-350 nm) were synthesized for the first time by employing a facile hydrothermal method. The prepared NPs were composited with a carboxyl group bearing conducting polymer (2,2:5,2-terthiophene-3-(p-benzoic acid, TBA)) to attain a stable sensor probe (pTBA/SrMoO4) which was analyzed using various surface analysis methods. The catalytic performance of the composite electrode was explored as an oxidation catalyst for biological molecules through anchoring on the conducting polymer layer, which functioned as a matrix to enhance the stability and selectivity of the sensor probe. The pTBA/SrMoO4 coated on glassy carbon displayed excellent electrocatalytic performance for the oxidation of some biologically important molecules, including dopamine (DA) in neuronal cells. The sensor immobilized with the catalyst showed an excellent response for DA with a dynamic range between 0.2 and 500 µM and a detection limit of 5 nM. The proposed sensor demonstrates the detection of trace DA released from PC12 cells under K+ stimulation, followed by inhibition of the release of exogenic DA by a Ca2+ channel blocker (nifedipine). The developed method provides an interesting way to monitor the effect of extracellular substances on living cells and the drug potency test.