Table 4

Quantification of carboxyl and sulfonate density using dye assay
Modification on glassy carbon Charge density Carboxyl density Sulfonate density
(molecules/cm2) (molecules/cm2) (molecules/cm2)
Step 1 in two-step functionalization Electrochemical grafting of 4-carboxyl phenyl diazonium for 8 min 1.3 × 1015 1.3 × 1015 -
Step 2 in two-step functionalization Carbodiimide coupling of dye 2.0 × 1015 1.07 × 1015 0.93 × 1015
One-step functionalization Electrochemical grafting of dye by amine oxidation for 8 min 0.9 × 1015 - 0.9 × 1015

Zhan et al.

Zhan et al. Nanoscale Research Letters 2013 8:279   doi:10.1186/1556-276X-8-279

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