A Novel Molecular Imprint Polymer Quartz Crystal Microbalance Nanosensor for the Detection of Andrographolide in the Medicinal Plant Extract

A novel quartz crystal microbalance (QCM) sensor based on molecular imprint polymer (MIP) has been developed for the detection of andrographolide in the medicinal plant extracts. The MIP and non-imprinted polymer (NIP) were synthesized using a precipitation polymerization method. The polymers were characterized by Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and cyclic voltammetry. Both MIP and NIP were deposited on quartz crystal platform using an electro-polymerization method. A linear Langmuir isotherm model revealed that the MIP-QCM sensor has the maximum binding sites 18.02 ng cm –2 . It was found that 92.8% of andrographolide was detected in 0.10 μg mL –1 of plant extract, and the limits of detection and quantification values were 1.21 and 4.02 ng cm –2 , respectively. This research showed that the andrographolide imprinted polymer could be used to detect and quantify andrographolide in Andrographis paniculata plant extract in both analytical separation and sensor development .