Antifouling and ultrasensitive biosensing interface based on self-assembled peptide and aptamer on macroporous gold for electrochemical detection of immunoglobulin E in serum

Abstract

Accurate detection of protein biomarkers in complex media remains a challenge due to severe nonspecific adsorption and biofouling, and sensing interfaces that combine the high sensitivity and antifouling ability are highly desirable. Herein, an antifouling sensing interface capable of sensitively assaying immunoglobulin E (IgE) in biological samples was constructed. The sensing interface was fabricated through the self-assembly of a zwitterionic peptide and the IgE aptamer onto a macroporous Au substrate, which was electrochemically fabricated with the aid of multilayer polystyrene nanospheres self-assembled on glassy carbon electrode. Due to the huge surface area arising from porous morphology and high specificity of aptamer, the developed electrochemical biosensor exhibits ultrahigh sensitivity and selectivity towards IgE, with the linear range of 0.1-10 pg mL, and a very low limit of detection down to 42 fg mL. Interestingly, owing to the presence of the zwitterionic peptide, the biosensing interface can satisfyingly reduce the nonspecific adsorption and fouling effect. Consequently, the biosensor was successfully applied to detect IgE in complex biological samples, indicating great promise of this peptide-based sensing interface for antifouling assays. Graphical abstract ᅟ.

Peptide-based antifouling aptasensor for cardiac troponin I detection by surface plasmon resonance applied in medium sized Myocardial Infarction

“…The increased value could be attributed to the hydrophobic effect of the SA [30]. As shown in igure 2d, the aptamer immobilized on the surface exhibited a decreased contact angle of 33.087° due to the h ydrophilicity of the a ptamer chain backbone [31]. T he constant change of contact angle at every step of biosensor construction con irmed the successful modi ication of Apt/SA/pep/Au.…”

Beyond Sensitive and Selective Electrochemical Biosensors: Towards Continuous, Real-Time, Antibiofouling and Calibration-Free Devices

“…Although these are considered as the “gold standard” materials, they show various defects such as their oxidative damage, poor water-solubility, and low protein resistance at high temperature. Peptides have come up as possible alternative antifouling materials in electrochemical affinity biosensors [ 30 , 31 , 32 ], providing additional advantages of biocompatibility, tunable and simple structure and synthesis [ 24 ].…”

Aptamers against Immunoglobulins: Design, Selection and Bioanalytical Applications

“…Thiol-labeled aptamers and zwitterionic peptides were immobilized to prevent non-specific adsorption owing to its hydrophobicity, neutral charge and a well-defined secondary structure, which ensures closely packed monolayer. IgE prevents the electron transfer between the [Fe(CN) 6 ] 3−/4− and the electrode, thereby the peak current in DPV was significantly dropped and 42 fg/mL (0.22 fM) detection limit was achievable [163]. The macroporous gold could be changed with poly (m-aminobenzoic acid) (PABA) electrochemical deposited on the electrode surface followed by immobilization of the aptamer and the zwitterionic peptide [164].…”