Multiplexed Electrochemical Immunosensors for Clinical Biomarkers

Abstract

Management and prognosis of disease requires the accurate determination of specific biomarkers indicative of normal or disease-related biological processes or responses to therapy. Moreover since multiple determinations of biomarkers have demonstrated to provide more accurate information than individual determinations to assist the clinician in prognosis and diagnosis, the detection of several clinical biomarkers by using the same analytical device hold enormous potential for early detection and personalized therapy and will simplify the diagnosis providing more information in less time. In this field, electrochemical immunosensors have demonstrated to offer interesting alternatives against conventional strategies due to their simplicity, fast response, low cost, high sensitivity and compatibility with multiplexed determination, microfabrication technology and decentralized determinations, features which made them very attractive for integration in point-of-care (POC) devices. Therefore, in this review, the relevance and current challenges of multiplexed determination of clinical biomarkers are briefly introduced, and an overview of the electrochemical immunosensing platforms developed so far for this purpose is given in order to demonstrate the great potential of these methodologies. After highlighting the main features of the selected examples, the unsolved challenges and future directions in this field are also briefly discussed.

Keywords: biomarkers; cancer; cardiovascular; microfluidic; multiplexed electrochemical immunosensors; paper electrodes.

Figure 1

Multiplexed electrochemical immunoplatform for the simultaneous determination of phosphorylated p53 at Ser392 (phospho-p53₃₉₂), Ser15 (phospho-p53₁₅), Ser46 (phospho-p53₄₆), and total p53 using electric field-driving and multi-enzyme labeling amplification. Reprinted from Ref. [8] with permission.

Figure 2

Scheme of the preparation and functioning of a multiplexed immunosensor for the determination of CEA and AFP involving stripping voltammetry of Ag catalytically deposited by gold nanolabels. Reprinted from Ref. [21] with permission.

Figure 3

Schematic display of the disposable dual magnetoimmunosensor prepared for the determination of NT-proBNP and CRP. Reprinted from Ref. [26] with permission.

Figure 4

Scheme of the different steps involved in the preparation and functioning of the dual GHRL and PYY immunosensors. Reprinted from Ref. [30] with permission.

Figure 5

Schematic illustration of the fundamentals for the preparation of a sandwich-type immunosensor for the simultaneous detection of four cancer biomarkers, CEA, AFP, CA125 and PSA. Inset shows an example of the DPV recorded voltammogram. Modified from Ref. [6] with permission.

Figure 6

Schematic illustration of the fabrication procedure of the immunosensor developed for CA15-3 and CA125 using NPG-MnO2 and THI or Fc as the redox probes. (A) Functionalization of NPG with cactus-like MnO2; (B) Steps involved in the preparation of the immunosensor. Reprinted from Ref. [37] with permission.

Figure 7

Preparation of HRP/PtPd/GS labeled redox probe branched antibodies (A). (B) Stepwise immunosensor fabrication process and DPV electrochemical responses. Reprinted from Ref. [12] with permission.

Figure 8

Scheme of the multiplexed electrochemical immunosensor for the simultaneous determination of AFP and CEA. Preparation of signal tags (A); preparation of MMIP and capture of AFP and CEA antigens followed by immunocomplexation and electrochemical detection (B). Reprinted from [43] with permission.

Figure 9

Multiplexed stripping voltammetric immunoassay using dendrimer-metal sulfide QD nanolabels (DE-QD) and tri-functionalized magnetic beads for the simultaneous determination of CA125, CA15-3 and CA19-9 cancer biomarkers: (a) preparation process and (b) measurement principle. Reprinted from [13] with permission.

Figure 10

Multiplexed electrochemical immunosensors for detection of CEA and AFP using CNSs coated with AgNPs or AuNPs and THI for immobilization of secondary antibodies. Preparation of immunoprobes (A). Immunosensor fabrication procedure and recorded voltammetric signals (B). Reprinted from [49] with permission.

Figure 11

(A) Scheme of the electrochemical immunosensor constructed for the simultaneous determination of IL-6 and IL-17 using two different tags to polystyrene spheres and Cd²⁺ and Fc as the electroactive labels. (B) SW voltammograms recorded for the simultaneous detection of (a–e) 5, 50, 100, 500 and 1000 pg·mL⁻¹ IL-6 (left) and IL-17 (right). Repinted from Ref. [53] with permission.

Figure 12

Scheme of the multiplexed electrochemical immunoassay for CEA and AFP using magnetic graphene nanosheets with immobilized capture antibodies as immunosensing probes, and multifunctional nanogold hollow microspheres (GHS) with encapsulated HRP-THI and HRP-Fc as distinguishable signal tags. Figure shows also some of the voltammograms recorded. Reprinted from Ref. [17] with permission.

Figure 13

Fabrication process of the paper electrode-based immunosensor exemplified for one analyte. Reprinted from Ref. [100] with permission.