Guanine (G) is one of the four DNA nucleotide bases, along with adenine (A), cytosine (C), and thymine (T). The sequence of these four nucleotide bases carries DNA’s genetic information. Within a double-stranded DNA molecule, guanine bases on one strand pair with cytosine bases on the opposite strand.
Derivatives of guanine play key regulatory roles in cellular functions, such as modulating neural cell activity and controlling transmembrane signal transduction—a process by which cells convert extracellular signals into intracellular responses. This mechanism allows cells to communicate with their environment and respond to external stimuli such as hormones, growth factors, or environmental changes.
Abnormal levels of guanine and its derivatives can lead to serious health issues. For instance, low GMP levels are associated with neurodegenerative brainstem disorders, while high concentrations of guanosine excretion are linked to carcinoma. Therefore, monitoring the concentration of guanine and its derivatives is crucial for understanding their biological roles and diagnosing related diseases.
Conventional methods for analysing guanine-containing compounds rely heavily on chromatographic techniques, such as high-performance liquid chromatography, gas chromatography, and mass spectrometry. While these diagnostic methods are highly sensitive and selective, they are also time-consuming, expensive, and difficult to operate. Additionally, in situ detection is challenging, as samples need to be extracted and processed before measurement. Detecting low concentrations of guanine in biological samples remains difficult due to its typically small presence in complex matrices. Another major challenge is electrode surface fouling, which occurs due to the adsorption of guanine oxidation products. This leads to decreased sensitivity and reproducibility over time, affecting the stability and efficiency of the sensor.
A recent paper published in the Journal of Alloys and Compounds by the University of Belgrade presents a novel approach for the electrochemical detection of guanine using Metal-Organic Frameworks (MOFs) and MOF-derived nanomaterials. These materials exhibit superior properties, including high chemical stability, relatively large specific surface areas, high porosity, and a tunable structure. Since the developed guanine sensors demonstrated excellent storage stability, repeatability, and selectivity, MOF-derived nanomaterials will continue to be used by the University of Belgrade to create MOBILES sensors able to detect pollution. Their real-world applicability was successfully tested by quantifying guanine in spiked urine samples with outstanding accuracy and precision.
Read more in the article published in the Journal of Alloys and Compounds: "MOF-Derived Nanoceria/Graphitic Carbon Nitride as an Efficient Electrochemical Modifier for Guanine Sensor with Diffusional Response."
Authors: Branka B. Petković, Hristo Kolev, Djordje Veljović, Dalibor M. Stanković, Bratislav Antić, Miloš Ognjanović
Journal of Alloys and Compounds
