Fig. 1. Flow chart of nanosensors preparation

Fig. 2. Flow chart of Terbutaline detection

Fig. 3. Au，Fe₃O₄ MNPs，Fe₃O₄/SiO₂和Fe₃O₄/SiO₂/Au-MNPs的TEM图

Fig. 4. Extinction spectra of Au and Fe₃O₄/SiO₂/Au-MNPs at different quantities of APTES

Fig. 5. The Raman spectra of TB at different concentrations (5×10⁻⁵ -5×10⁻⁹ mol/L).

Fig. 6. Linear plot of intensity of the 1 034 cm⁻¹ peak for various concentrations of TB