Developing a versatile and novel electrochemical sensor for rapid detection of 4-Nitrophenol (4-NP) is quite necessary, as the ecological balance has accented with increase in pollution. A novel electrocatalyst is quite necessary for rapid and real-time analysis to this we have chosen boron-doped graphene quantum dots (B-GQD) anchored on functionalized mutli-walled carbon nanotubes (f-MWCNT) for electrochemical determination of 4-NP. Here, the B-GQD/f-MWCNT provided excellent characteristic properties exhibiting electron-hole pair following first order brillouin zone using first order kinetics. Transmission electron microscopy (TEM) displays B-GQD’s anchored on f-MWCNT with a well-defined spherical shape, without any comprehensive agglomeration. The prepared B-GQD/f-MWCNT nanocomposite was electro-spun on carbon cloth which displayed an excellent electrocatalytic activity for 4-NP with a Limit of Detection of 11.3 nM with a ultra-high sensitivity of 83.17 µAµM^-1cm^-2, which established a new selectivity by interfering with co-existing phenolic, cationic and anionic compounds. Real-time analysis was carried in human blood, urine, river water, industrial water and tap water to identify and determine the traces of 4-NP which resulted in satisfactory recoveries in comparison with HPLC data. Overall mechanism of detection was shown in Scheme.

Keywords: 4-Nitrophenol; quantum dots; graphene; human blood; electrochemical sensor.