Ultrasensitive antibody-aptamer plasmonic biosensor for malaria biomarker detection in whole blood

Abstract

Development of plasmonic biosensors combining reliability and ease of use is still a challenge. Gold nanoparticle arrays made by block copolymer micelle nanolithography (BCMN) stand out for their scalability, cost-effectiveness and tunable plasmonic properties, making them ideal substrates for fluorescence enhancement. Here, we describe a plasmon-enhanced fluorescence immunosensor for the specific and ultrasensitive detection of Plasmodium falciparum lactate dehydrogenase (PfLDH)—a malaria marker—in whole blood. Analyte recognition is realized by oriented antibodies immobilized in a close-packed configuration via the photochemical immobilization technique (PIT), with a top bioreceptor of nucleic acid aptamers recognizing a different surface of PfLDH in a sandwich conformation. The combination of BCMN and PIT enabled maximum control over the nanoparticle size and lattice constant as well as the distance of the fluorophore from the sensing surface. The device achieved a limit of detection smaller than 1 pg/mL (<30 fM) with very high specificity without any sample pretreatment. This limit of detection is several orders of magnitude lower than that found in malaria rapid diagnostic tests or even commercial ELISA kits. Thanks to its overall dimensions, ease of use and high-throughput analysis, the device can be used as a substrate in automated multi-well plate readers and improve the efficiency of conventional fluorescence immunoassays.

Systematic Evolution of Ligands by Exponential Enrichment Technologies and Aptamer-Based Applications: Recent Progress and Challenges in Precision Medicine of Infectious Diseases

“…Thus, the application of detections that require expensive equipment or complex laboratory sites is significantly limited in these areas. In this case, a deal of aptamer-based biosensors has been developed for the identification of parasites due to their low cost, simplicity, portability ( Lee et al, 2012 ; Singh et al, 2019a ; Singh et al, 2019b ; Frezza et al, 2020 ; Minopoli et al, 2020 ). Take the diagnosis of malaria as an example, Singh et al established instrument-based and instrument-free approaches for pan malaria and P. falciparum species based on aptamers specific to Plasmodium lactate dehydrogenase (PLDH) and Plasmodium falciparum glutamate dehydrogenase (P f GDH) respectively ( Singh et al, 2019a ).…”

Oligonucleotide aptamers for pathogen detection and infectious disease control

“…Later, they immobilized biotinylated HMG-box onto streptavidin-coated magnetic beads for protein-SELEX and developed several DNA aptamers of potential use for malaria diagnosis. Minopoli et al developed an antibody-aptamer plasmonic biosensor to detect P. falciparum lactate dehydrogenase (PfLDH) by immobilizing PfLDH-specific antibodies onto gold nanoparticles for PfLDH capture and labeling the PfLDH-specific aptamer to detect the captured PfLDH 223 . Using this aptasensor, the detection limit was as low as 1 pg/mL in blood samples.…”

Graphene Enabled Low‐Noise Surface Chemistry for Multiplexed Sepsis Biomarker Detection in Whole Blood

“…[ 2 ] Among the variety of biosensing platforms, electrochemical (EC) biosensors would be preferred to use for this application due to their potential for optimal detection limits, cost‐effective integration with diagnostic readers, and low power instrumentation requirements. [ 3 ] Optical detection of biomarkers from whole blood has recently been achieved using plasmonic biosensors, [ 4 ] microneedle based sensors utilizing localized surface plasmon resonance (SPR), [ 5 ] and even smartphone‐based systems. [ 6 ] While individual biomarker detection has been demonstrated in whole blood using EC systems, [ 7 ] parallel detection of multiple biomarkers has been more challenging.…”