Aptamer-based biosensors for the diagnosis of sepsis

Abstract

Sepsis, the syndrome of infection complicated by acute organ dysfunction, is a serious and growing global problem, which not only leads to enormous economic losses but also becomes one of the leading causes of mortality in the intensive care unit. The detection of sepsis-related pathogens and biomarkers in the early stage plays a critical role in selecting appropriate antibiotics or other drugs, thereby preventing the emergence of dangerous phases and saving human lives. There are numerous demerits in conventional detection strategies, such as high cost, low efficiency, as well as lacking of sensitivity and selectivity. Recently, the aptamer-based biosensor is an emerging strategy for reasonable sepsis diagnosis because of its accessibility, rapidity, and stability. In this review, we first introduce the screening of suitable aptamer. Further, recent advances of aptamer-based biosensors in the detection of bacteria and biomarkers for the diagnosis of sepsis are summarized. Finally, the review proposes a brief forecast of challenges and future directions with highly promising aptamer-based biosensors.

Keywords: Aptamer-based biosensors; Diagnosis; Nanomaterials; Sepsis.

Fig. 1

The analysis of keyword co-occurrences on aptamer and (nano)biointerface

Fig. 2

Aptamer-based biosensors in the detection of bacteria and biomarkers for the diagnosis of sepsis

Fig. 3

The process of SELEX

Fig. 4

Bead-based amplification in the detection of unbound S. aureus using aptamer-conjugated GNPs [44]

Fig. 5

The Apt-Fe₃O₄@mTiO₂ nanosensor (A–D). A Conceptual strategies to enrich and identify pathogenic bacteria in human blood. Top: conventional blood culture. Down: the aptamer-based capture platform. B Photographs and agar plates showing the bacteria capture with and without a bar magnet. C Schematic representation of detection time for enriching and identifying pathogen in human blood samples based on that aptamer-based capture platform (left) and conventional blood culture (right). D Bacteria counted numbers enriched by Apt-Fe₃O₄@mTiO₂ nanosensor at a low concentration range (10–2000 CFU/mL) [45]. The Fe₃O₄-Ce6-Apt nanosystem (E–H). E Schematic illustration of strategies for early sepsis diagnosis and extracorporeal blood disinfection based on Fe₃O₄-Ce6-Apt nanosystem. F Illustration of the process of Fe₃O₄-Ce6-Apt nanosystem-based strategy for the bacterial enrichment and identification within 1.5 h. G Agar plate photographs for live bacterial units. The blood samples containing S. aureus (10⁶ CFU) were incubated with Fe₃O₄-Ce6-Apt nanosystem before and after NIR laser irradiation for 5 min. H Photographs of the mice transfused with the blood samples containing S. aureus (10⁶ CFU) with and without disinfection treatment at different times [68]

Fig. 6

The scheme of GN6 ELAA and the specificity of GN6 to some OMVs [49]

Fig. 7

Scheme of vertical capacitance aptamer-functionalized sensor [46]

Fig. 8

Schematic diagram of the preparation and working principle of Apt/AuAC/Au sensor [52]

Fig. 9

A Schematic diagram of the fabrication of PEI-rGO-MoS2. B Schematic representation of the coating of the aptamer sensor [55]

Fig. 10

The interaction principle of determination of LPS by coupling FAM-aptamer and rGO on a microfluidic biochip. a Schematic diagram of the fluorescence formation of LPS; b Schematic representation of the PDMS microfluidic CI-ES-chip; c Voltage scheme applied for the LPS preconcentration and the CI-ES mechanism [59]

Fig. 11

The process of the sandwich-style and color changes [60]

Fig. 12

The experimental setup of a fiber optic biosensor [65]

Fig. 13

A decrease in the photoluminescence of the nanosensor when CRP binds to the DNA aptamer [67]