Fabrication of a porphyrin-based electrochemical biosensor for detection of nitric oxide released by cancer cells

Abstract

A b s t r a c t I n t h i s r e po r t 5 ,1 0, 15 ,2 0-t etr ak i s ( 4 -methoxyphenyl)porphyrin (H 2 TMPP) has been used as electrode material for an easy and direct detection of NO in cancer cells using different electrochemical techniques. Cyclic voltammograms of H 2 TMPP-modified GCE in aqueous electrolyte showed oxidation peaks at 0.5 and 0.73 Vand reduction peak at 0.64 Vand a small peak at 0.4 V which are attributed to the redox processes of the system. The anodic and cathodic peak currents were proportional to the square root of the scan rate indicating a diffusion controlled mechanism. The H 2 TMPP-modified GC electrode exhibits a good stability after several circles. The fabricated electrode system was used to probe the concentration change of NO in HeLa cells using chronoamperometry. The NO sensor registered an amperometric current sensitivity of 0.0138 nA/μL with a linear correlation coefficient of 0.99571 in the presence of extracellular NO released upon activation of HeLa cells. Via confocal laser scanning microscopy, it has been demonstrated that H 2 TMPP could be used as a fluorescent indicator for cell imaging.

Recent Advances in Phthalocyanine and Porphyrin-Based Materials as Active Layers for Nitric Oxide Chemical Sensors

“…Electrochemical sensors offer the advantage of low detection limit, fast response, easy manufacturing and small size, allowing real-time and fast measurement of NO concentration in water media and biological samples [ 32 , 59 ]. A classical three-electrode configuration consisting of a working electrode, reference electrode and counter electrode is usually employed to detect NO.…”

“…The literature describes examples of the determination of NO by electrochemical methods in real biological samples. For example, Chandra et al [ 59 ] reported that the modification of GCE by 5,10,15,20-tetrakis(4-methoxyphenyl) porphyrin (H 2 TMPP) allows the direct detection of NO in cultured cervical cancer (HeLa) cells. The three-electrode system including a Pt wire as counter electrode, silver reference electrode and GCE as working electrode was used for electrochemical NO detection.…”

“…An important step in the development of the sensor is also the method of modification of the electrode surface, which provides good adhesion and charge transfer between the active layer and the electrode surface. The methods, which are widely used for the modification of electrodes with phthalocyanine, porphyrins and hybrid materials, include immersion in the corresponding solution [ 56 ], drop and dry [ 59 , 64 , 77 , 78 ], electrodeposition or electropolymerization [ 58 , 73 , 74 ]. To prevent leaching of the electroactive component, the active layers are sometimes covered with a polymeric layer that does not prevent the penetration of analyte molecules.…”

“…A useful strategy aimed at improving the selectivity of the sensor to NO involves the use of various polymeric membranes, e.g., Nafion, which provide a sufficient barrier for various anionic interfering analytes, especially nitrite [ 59 , 61 ]. Indeed, the chemical modification of electrode surfaces with metal phthalocyanine and porphyrin films, polymer and polyelectrolytes expands the scope of application of such new-design electrodes and provides many opportunities for their use in various experimental conditions.…”

Porphyrins in troubled times: a spotlight on porphyrins and their metal complexes for explosives testing and CBRN defense

“…This can be evaluated by irradiation and measuring attenuation of the incident radiation or by detecting the secondary radiation emitted. Absorbance changes, fluorescence quenching (turn-off), and fluorescence turn-on have been monitored to optochemically detect analytes of clinical, environmental, and security-related interest, including hydrochloric acid, 109,110 NO released by cancer cells, 59 pollutants, [75][76][77][78][79] and explosives, [69][70][71][72][73][74] to name a few, at high sensitivity (vide supra). The potential and increasing use of metalloporphyrins for molecular recognition and beyond, e.g., explosives detection, and disease diagnostics, is not least due to their ability to detect a broader range of volatile fingerprints through variation of the complexed metal ion and the macrocycle substitution pattern.…”