Abstract
In this work, we fabricated a novel graphene film composite biosensor for microcystin-LR detection as an alternative to time-consuming, expensive, non-portable and often skills-demanding conventional methods of analysis involved in water quality monitoring and assessment. Excellent linear correlation (R2 = 0.99) of the electron-transfer resistance was achieved over a wide range of microcystin-LR (MC-LR) concentration, i.e. 0.005–10 μg/L. As-prepared graphene film composite biosensors can specifically detect MC-LR with remarkable sensitivity and detection limit (2.3 ng/L) much lower than the World Health Organization (WHO) provisional guideline limit of microcystin-LR concentration (i.e. 1 μg/L) in different water sources. Their great potential can be attributed to large active surface area of graphene film and efficient charge transfer process enabled by their high conductivity. Developed graphene film composite biosensors were also successfully applied to determination of MC-LR in several environmental water samples with high detection recovery, which offers a promising possibility of large-scale manufacture of sensor tips due to their macroscopic free-standing nature, the scalable fabrication route and easily tunable size.
Highlights
Access to safe drinking water and their sufficient treatment are of paramount importance to people’s health and quality of life in any community around the world[1,2]
Many efforts have been made to utilize these outstanding properties of graphene for macroscopic applications such as flexible/stretchable electronics as alternatives to the time-consuming, expensive, non-portable and often skills-demanding conventional methods of analysis involved in water quality assessment[25,26,27,28]
Intra-assay reproducibility of fabricated graphene film (GF) biosensors was assessed by replicative electrochemical impedance spectroscopy (EIS) measurement of each one of five MC-LR concentrations (i.e. 0.005 to 10 μg/L) using three different GF biosensors, of which the relative standard deviations (RSD) were 4.5%, 7.3%, 13%, 10.8% and 5.2%, respectively. These results have demonstrated developed GF biosensor as a very effective tool for monitoring the variation of MC-LR concentration in water in terms of good reproducibility
Summary
Access to safe drinking water and their sufficient treatment are of paramount importance to people’s health and quality of life in any community around the world[1,2]. Many efforts have been made to utilize these outstanding properties of graphene for macroscopic applications such as flexible/stretchable electronics as alternatives to the time-consuming, expensive, non-portable and often skills-demanding conventional methods of analysis involved in water quality assessment[25,26,27,28]. Their fabrication in terms of desirable form and better morphological control is still challenging at the moment. Much improved detection range of MC-LR (i.e. an order of magnitude lower) and biosensor linear response (i.e. R2 > 0.99) were achieved in comparison with our previous study using another type of graphene electrode, which was probably due to more uniform coating of graphene film[33]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
