Fig. 4From: Development of gold nanoparticles biosensor for ultrasensitive diagnosis of foot and mouth disease virusThe zeta potential of the naked AuNPs and AuNPs-FMDV biosensor: curve a illustrates a peak of zeta potential distribution representing surface charges (− 38.9 m V) of naked AuNPs. Curve b illustrates a peak of zeta potential distribution representing slight decrease in AuNPs surface charge (from − 38.9 to − 18.3 m V) due to the conjugation process and forming of AuNPs-FMDV biosensor (b)Back to article page