Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Abstract

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.

Carbon-Based Materials in Photodynamic and Photothermal Therapies Applied to Tumor Destruction

“…Within CBM, graphene has become one of the most studied materials owing to its unique chemical and physical properties [ 32 , 33 ] which have encouraged its application in diverse fields such as electronics, material science, energy, and biomedicine, including the treatment of the COVID-19 disease [ 34 , 35 , 36 , 37 ]. Regarding bio-applications, the versatility of graphene has allowed its assessment as an antimicrobial agent [ 38 ], in sensors [ 39 ], drug delivery [ 40 ], bioimaging [ 41 ], regenerative medicine [ 42 ], cancer treatment [ 43 , 44 ], and photodynamic and photothermal therapies [ 45 , 46 ]. However, the hydrophobicity of the pristine graphene has turned into a drawback when affinity with physiological solutions or water is desirable [ 47 ].…”

Carbon-Based Materials in Photodynamic and Photothermal Therapies Applied to Tumor Destruction

“…Within CBM, graphene has become one of the most studied materials owing to its unique chemical and physical properties [32,33], which have encouraged its application in diverse fields such as electronics, material science, energy, and biomedicine, including the treatment of COVID-19 disease [34][35][36][37]. Regarding bio-applications, the versatility of graphene has allowed its assessment as an antimicrobial agent [38], in sensors [39], in drug delivery [40], bioimaging [41], regenerative medicine [42], cancer treatment [43,44], and photodynamic and photothermal therapies [45,46]. However, the hydrophobicity of the pristine graphene has turned into a drawback when affinity with physiological solutions or water is desirable [47].…”

Electrochemical Biosensor Based on Laser-Induced Graphene for COVID-19 Diagnosing: Rapid and Low-Cost Detection of SARS-CoV-2 Biomarker Antibodies

“…Several modifications are reported, including the combination of these materials with organic polymers, biomolecules and various types of inorganic nanoparticles, ranting specificity and selectivity, aiding their interaction with the target analyte, resulting in an accurate detection. [21,22]. The production of graphene-based materials takes place through various techniques, such as chemical vapor deposition (CVD), mechanical exfoliation, and more recently, laser-induced graphene (LIG), a technique developed by Lin et al (2014) [23].…”