Multi-branched PdPt nanodendrites decorated amino-rich Fe-based metal-organic framework as signal amplifier for ultrasensitive electrochemical detection of prolactin

Abstract

Prolactin (PRL) disorder is one of the most pervasive issues in clinical endocrinology, thus, accurate and sensitive quantification of PRL possesses considerable significance in endocrine diseases diagnosis. Inspired by the excellent electrochemical properties of bimetallic nanodendrites (NDs), an enzyme-free sandwich-type electrochemical immunosensor was fabricated herein for ultrasensitive detection of PRL, based on multi-branched PdPt NDs decorated amino-rich Fe-based metal-organic framework for signal amplification and gold nanoparticles coated amino-functionalized graphene sheet (Au NPs@NH 2 -GS) for sensing platform. The integration of PdPt NDs and NH 2 -MIL-53(Fe) (PdPt NDs@NH 2 -MIL-53(Fe)) allowed efficient labeling of secondary antibodies (Ab 2 ), featuring unparalleled biocompatibility and electrocatalytic activity toward hydrogen peroxide (H 2 O 2 ) reduction. Additionally, Au NPs@NH 2 -GS with high surface area and superior conductivity not only enhanced electron transfer efficiency, but also improved loading amounts of primary antibodies (Ab 1 ). Benefiting from the outstanding synergistic effect of these components, this immunosensor demonstrated a broad linear range (0.001–500 ng/mL) and low detection limit of 1.15 pg/mL (S/N = 3), along with characterizing excellent reproducibility, specificity and stability. Particularly, the proposed immunosensor permitted PRL levels detection in clinical samples with satisfactory results, signifying the significant potential of application in the clinical diagnosis. Schematic illustration of the designed electrochemical immunosensor for prolactin detection. • An enzyme-free immunosensor was developed for ultrasensitive prolactin detection. • PdPt NDs@NH 2 -MIL53(Fe) with high catalytic activity was used as signal amplifier. • The immunosensor exhibited a wide linear range and low limit detection. • This method was successfully applied to detect prolactin in real serum samples.