Using density functional theory calculations, we investigated potential application of BC3 nanosheet and nano- tube in amphetamine (AM) drug detection. The AM interacts with a B atom of the sheet and tube via its –NH2 group with adsorption energies about −10.7 and −15.5 kcal/mol, respectively. The electronic properties of sheet and tube are not affected by AMdrugwhichmakes theminappropriate for detection process. To overcome this problem, they are dopedwith Si atom. The reactivity and sensitivity of the Si-doped systems significantly in- crease and these structuresmay be promising sensors for AMdetection. The adsorption energies are about−21.3 and −24.5 kcal/mol for Si-doped sheet and tube, respectively. The electrical conductivity of the Si-doped nano- tubemuchmore increases at the presence of AMcompared to the Si-doped sheet. But the Si-doped sheet benefits from a short recovery time (~0.4 s) compared to the Si-doped nanotube (~87.5 s).