A novel biosensor for early diagnosis of liver cancer cases using smart nano-magnetic metal–organic framework

For the first time, alpha-fetoprotein (AFP) quantification as an early test for liver cancer diagnosis competing with other interfering analytes and factors based on a novel nano-magnetic metal–organic framework (MOF) was investigated. The novel nano-magnetic MOF was synthesized via a simple preparation method, and characterized using various techniques. The X-ray photoelectron spectrum of the nano-magnetic MOF shows Cu 2p, O 1s, N 1s and C 1s peaks that evidence the presence of these elements in the sample without any impurities. Scanning and transmission electron microscopy images show the nano-magnetic MOF with average size between 22 and 43 nm. The results of a photoluminescence study show that the nano-magnetic MOF exhibits strong emission at 418 nm after excitation at 354 nm. Moreover, a Stern–Völmer graph shows a linear calibration curve over an AFP concentration range 1.0–520 ng ml⁻¹ with a correlation coefficient of 0.997, detection limit of 1.18 ng ml⁻¹ and quantitation limit of 3.58 ng ml⁻¹. According to the marked quenching of the photoluminescence intensity of the nano-magnetic MOF using various concentrations of AFP, it was successfully used as a biosensor for AFP in serum samples collected from hepatitis patients in addition to healthy males and females. The quenching mechanism was well studied, and found to be a dynamic type. The present work offers a simple, low-cost, room-temperature and rapid technique, being non-time-consuming, highly accurate, selective and highly sensitive compared with most published methods.