Comment on: "Structural, optical and dielectric studies of Ag nanoparticles decorated by herceptin" [Physica E 114 (2019) 113562].

In a recent paper [Physica E 114(2019) 113562] Jafarzadeh et al. have studied the optical and dielectric properties of Ag nanoparticles decorated by herceptin. The reflectance spectra of the specimens have been calculated using an incorrect approach and obtained results are unreasonable. Also, the erroneous values of reflectance have been used to study the optical properties of the samples. Consequently, reported optical parameters that have been calculated based on reflectance such as refractive index, extinction coefficient, as well as real and imaginary parts of the optical dielectric constant are incorrect. • The reflectance spectra have been calculated using a wrong approach. • The reported values of the refractive index are incorrect. • The reported values of the extinction coefficient are erroneous. • The calculated values of the optical dielectric constant are wrong. [ABSTRACT FROM AUTHOR]