A near-infrared photoelectrochemical aptasensor based on a Yb–Bi₂S₃/AuNP nanocomposite for determining miRNA-155, a biomarker for allergic rhinitis

MiRNA-155 is a reliable biomarker for cancers and allergic rhinitis and also plays a critical role in regulating gene expression and mediating the allergic TH2 process. The accurate determination of miRNA-155 is significant for diagnosing allergic rhinitis, especially for children. Herein, Yb-Bi₂S₃ nanorods were prepared through a hydrothermal method. Gold nanoparticles (AuNPs) were then assembled onto the Yb-Bi₂S₃ nanorods surface to obtain a Yb-Bi₂S₃/AuNP nanocomposite. Yb-Bi₂S₃/AuNP nanocomposite was used as a photoactive element for fabricating a near-infrared photoelectrochemical aptasensing platform by assembling an aptamer for the specific recognition of miRNA-155. The variation in photocurrent of the photoelectrochemical aptasensor before and after recognizing miRNA-155 was linearly related to the miRNA-155 concentration in the range of 1.0 fmol L^-1 to 1.0 nmol L^-1. The detection limit was calculated to be 0.34 fmol L^-1. The developed photoelectrochemical aptasensor was successfully employed for determining miRNA-155 in serum samples with satisfactory results, indicating that it possessed practical application in the determination of miRNA-155 in real samples.