Naturally manufactured biochar materials based sensor electrode for the electrochemical detection of polystyrene microplastics

In recent times, microplastics have become a disturbance to both aquatic and terrestrial ecosystems and the ingestion of these particles can have severe consequences for wildlife, aquatic organisms, and even humans. In this study, two types of biochars were manufactured through the carbonization of naturally found starfish (SF-1) and aloevera (AL-1). The produced biochars were utilized as sensing electrode materials for the electrochemical detection of ∼100 nm polystyrene microplastics (PS). SF-1 and AL-1 based biochars were thoroughly analyzed in terms of morphology, structure, and composition. The detection of microplastics over biochar based electrodes was carried out by electrochemical studies. From electrochemical results, SF-1 based electrode exhibited the detection efficiency of ∼0.2562 μA/μM∙cm² with detection limit of ∼0.44 nM whereas, a high detection efficiency of ∼3.263 μA/μM∙cm² was shown by AL-1 based electrode and detection limit of ∼0.52 nM for PS (100 nm) microplastics. Process contributed to enhancing the sensitivity of AL-1 based electrode might associate to the presence of metal-carbon framework over biochar's surfaces. The AL-1 biochar electrode demonstrated excellent repeatability and detection stability for PS microplastics, suggesting the promising potential of AL-1 biochar for electrochemical microplastics detection.