Study of ethosuximide detection using a novel molecularly imprinted electrochemiluminescence sensor based on tris(2,2′-bipyridyl) ruthenium(II)@nitrogen doped graphene quantum dots

A novel molecularly imprinted electrochemiluminescene (ECL) sensor was fabricated for the detection of ethosuximide . The new Ru(pby) 3 2+ @N-GQDs (tris(2,2′-bipyridyl) ruthenium(II)@nitrogen doped graphene quantum dots) nanocomposite was synthesized by electrostatic interaction between Ru(pby) 3 2+ and N-GQDs, which showed excellent and stable ECL properties. And then dopamine as functional monomer and ethosuximide as template molecule were co -polymerized by hydrogen bonding on the surface of Ru(pby) 3 2+ @N-GQDs/Nafion. After ethosuximide was extracted with H 2 SO 4 , the molecularly imprinted cavities in film were formed. When ethosuximide rebound onto imprinted cavities again, the ECL intensity of Ru(pby) 3 2+ @N-GQDs decreased. Based on this principle, the quantitative relationship between the concentration of ethosuximide ( c ) and the variation of ECL intensity (Δ I ECL ) was established. Namely the Δ I ECL depended linearly on the log c in the range from 5.00 × 10 −7 to 1.00 × 10 −4  mol/L with a detection limit of 3.00 × 10 −7  mol/L (S/N = 3), and the correlation coefficient was 0.9984. The proposed sensor was also applied in plasma and urine samples with recovery in range from 97.80% to 106.2% (RSD < 6.3%).