Carbon nanomaterials have attracted researchers in pharmaceutical applications due to their outstanding properties and flexible dimensional structures. Carbon nanomaterials (CNMs) have electrical properties, high thermal surface area, and high cellular internalization, making them suitable for drug and gene delivery, antioxidants, bioimaging, biosensing, and tissue engineering applications. There are various types of carbon nanomaterials including graphene, carbon nanotubes, fullerenes, nanodiamond, quantum dots and many more that have interesting applications in the future. The functionalization of the carbon nanomaterial surface could modify its chemical and physical properties, as well as improve drug loading capacity, biocompatibility, suppress immune response and have the ability to direct drug delivery to the targeted site. Carbon nanomaterials could also be fabricated into composites with proteins and drugs to reduce toxicity and increase effectiveness in the pharmaceutical field. Thus, carbon nanomaterials are very effective for applications in pharmaceutical or biomedical systems. This review will demonstrate the extraordinary properties of nanocarbon materials that can be used in pharmaceutical applications.

Theophylline is a drug with a narrow therapeutic range. Electrochemical sensors are a potentially effective method for detecting theophylline concentration to prevent toxicity. In this work, a simple modification of a boron-doped diamond electrode using nickel nanoparticles was successfully performed for a theophylline electrochemical sensor. The modified electrode was characterized using a scanning electron microscope and X-ray photoelectron spectroscopy. Square wave voltammetry and cyclic voltammetry methods were used to study the electrochemical behavior of theophylline. The modified nickel nanoparticles on the boron-doped diamond electrode exhibited an electrochemically active surface area of 0.0081 cm², which is larger than the unmodified boron-doped diamond’s area of 0.0011 cm². This modified electrode demonstrated a low limit of detection of 2.79 µM within the linear concentration range from 30 to 100 µM. Moreover, the modified boron-doped diamond electrode also showed selective properties against D-glucose, ammonium sulfate, and urea. In the real sample analysis using artificial urine, the boron-doped diamond electrode with nickel nanoparticle modifications achieved a %recovery of 105.10%, with a good precision of less than 5%. The results of this work indicate that the developed method using nickel nanoparticles on a boron-doped diamond electrode is promising for the determination of theophylline.

Theophylline (TP) is a methylxanthine derivative, which serves as a valuable compound in treating respiratory disorders and acts as a bronchodilator agent. However, TP has a limited therapeutic range (20–100 μmol L⁻¹), demanding precise monitoring to prevent potential drug toxicity even with slight level fluctuations during treatment. Thus, to overcome this limitation, electrochemical methods have been extensively used due to their efficacy in achieving sensitivity, selectivity, and accuracy. In the context of electrochemical sensors, nanocarbon-based materials have gained widespread recognition for their extensive applications. Therefore, this review aims to explore the latest advancements in carbon-based electrodes particularly used for the precise determination of TP through electrochemical methods. The results are expected to provide insights into the profound significance of the methods in enhancing the accuracy and sensitivity for the detection of TP.