TY - JOUR
T1 - Reusable and highly sensitive SERS immunoassay utilizing gold nanostars and a cellulose hydrogel-based platform
AU - Oliveira, Maria João
AU - Cunha, Inês
AU - de Almeida, Miguel P.
AU - Calmeiro, Tomás
AU - Fortunato, Elvira
AU - Martins, Rodrigo
AU - Pereira, Luís
AU - Byrne, Hugh J.
AU - Pereira, Eulália
AU - Águas, Hugo
AU - Franco, Ricardo
N1 - Funding Information:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50025%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F04378%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50006%2F2020/PT#
info:eu-repo/grantAgreement/FCT/3599-PPCDT/PTDC%2FNAN-MAT%2F30589%2F2017/PT#
info:eu-repo/grantAgreement/FCT/OE/SFRH%2FBD%2F126409%2F2016/PT##
This work was funded by FEDER funds through the COMPETE 2020 Programme and National Funds through the FCT?Funda??o para a Ci?ncia e a Tecnologia, I. P., under the scope of the project. This work also received funding from the European Community's H2020 program under grant agreement No. 716510 (ERC-2016-STG TREND), 640598 (ERC-StG-2014, NEWFUN), and 685758 (1D-Neon). This work was supported by the Applied Molecular Biosciences Unit - UCIBIO and Associate Laboratory for Green Chemistry - LAQV which are financed by Portugal national funds from , and grant and fellowships from the FCT/MCTES and MIT Portugal PhD Program (to I. C. and M. J. O., respectively). Professor C?sar Laia (LAQV-REQUIMTE, Faculdade de Ci?ncias e Tecnologia, Universidade NOVA de Lisboa, Portugal) is acknowledged for permitting the use of DLS equipment. Professor Ludwig Krippahl (NOVA LINCS, Faculdade de Ci?ncias e Tecnologia, Universidade NOVA de Lisboa, Portugal) is acknowledged for developing the gel analysis application eReuss. M. J. O. acknowledges Roc?o Palomares Jurado PhD for visualisation/data presentation support and continued interest in the project. M. J. O. acknowledges David Peitinho MSc for help and advice in Python script. Diego Wiechers de Carvalho BSc is acknowledged for purifying the recombinantPlasmodium falciparumhistidine-rich protein 2 sample and Daniela Gomes PhD for providing SEM images.
Funding Information:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50025%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F04378%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50006%2F2020/PT#
This work was funded by FEDER funds through the COMPETE 2020 Programme and National Funds through the FCT---Fun-dação para a Ciência e a Tecnologia, I. P., under the scope of the project. This work also received funding from the European Community’s H2020 program under grant agreement No. 716510 (ERC-2016-STG TREND), 640598 (ERC-StG-2014, NEWFUN), and 685758 (1D-Neon). This work was supported by the Applied Molecular Biosciences Unit – UCIBIO and Associate Laboratory for Green Chemistry – LAQV which are financed by Portugal national funds from /2016 and SFRH/BD/132057/2017 from the FCT/MCTES and MIT Portugal PhD Program (to I. C. and M. J. O., respectively). Professor César Laia (LAQV-REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Portugal) is acknowledged for permitting the use of DLS equipment. Professor Ludwig Krippahl (NOVA LINCS, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Portugal) is acknowledged for developing the gel analysis application eReuss. M. J. O. acknowledges Rocío Palomares Jurado PhD for visualisation/data presentation support and continued interest in the project. M. J. O. acknowledges David Peitinho MSc for help and advice in Python script. Diego Wiechers de Carvalho BSc is acknowledged for purifying the recombinant Plasmodium falciparum histidine-rich protein 2 sample and Daniela Gomes PhD for providing SEM images.
Publisher Copyright:
© The Royal Society of Chemistry 2021.
PY - 2021/9/28
Y1 - 2021/9/28
N2 - The development of robust and sensitive point-of-care testing platforms is necessary to improve patient care and outcomes. Surface-enhanced Raman scattering (SERS)-based immunosensors are especially suited for this purpose. Here, we present a highly sensitive and selective SERS immunoassay, demonstrating for example the detection of horseradish peroxidase (HRP), in a sandwich format. The strength of our biosensor lies in merging: (i) SERS-immunotags based on gold nanostars, allowing exceptional intense SERS from attached Raman probes, covalent attachment of anti-HRP antibodies by a simple chemical method providing exceptional antigen binding activity; (ii) the ease of preparation of the capture platform from a regenerated cellulose-based hydrogel, a transparent material, ideal for microfluidics applications, with low background fluorescence and Raman signal, particularly suited for preserving high activity of the covalently bound anti-HRP antibodies. The sandwich complexes formed were characterised by atomic force microscopy, and by scanning electron microscopy coupled with electron diffraction spectroscopy; and (iii) the robustness of the simple Classical Least Squares method for SERS data analysis, resulting in superior discrimination of SERS signals from the background and much better data fitting, compared to the commonly used peak integral method. Our SERS immunoassay greatly improves the detection limits of traditional enzyme-linked immunosorbent assay approaches, and its performance is better or comparable to those of existing SERS-based immunosensors. Our approach successfully overcomes the main challenges of application at point-of-care, including increasing reproducibility, sensitivity, and specificity, associated with an environmentally friendly and robust design. Also, the proposed design withstands several cycles of regeneration, a feature absent in paper-SERS immunoassays and this opens the way for sensitive multiplexing applications on a microfluidic platform.
AB - The development of robust and sensitive point-of-care testing platforms is necessary to improve patient care and outcomes. Surface-enhanced Raman scattering (SERS)-based immunosensors are especially suited for this purpose. Here, we present a highly sensitive and selective SERS immunoassay, demonstrating for example the detection of horseradish peroxidase (HRP), in a sandwich format. The strength of our biosensor lies in merging: (i) SERS-immunotags based on gold nanostars, allowing exceptional intense SERS from attached Raman probes, covalent attachment of anti-HRP antibodies by a simple chemical method providing exceptional antigen binding activity; (ii) the ease of preparation of the capture platform from a regenerated cellulose-based hydrogel, a transparent material, ideal for microfluidics applications, with low background fluorescence and Raman signal, particularly suited for preserving high activity of the covalently bound anti-HRP antibodies. The sandwich complexes formed were characterised by atomic force microscopy, and by scanning electron microscopy coupled with electron diffraction spectroscopy; and (iii) the robustness of the simple Classical Least Squares method for SERS data analysis, resulting in superior discrimination of SERS signals from the background and much better data fitting, compared to the commonly used peak integral method. Our SERS immunoassay greatly improves the detection limits of traditional enzyme-linked immunosorbent assay approaches, and its performance is better or comparable to those of existing SERS-based immunosensors. Our approach successfully overcomes the main challenges of application at point-of-care, including increasing reproducibility, sensitivity, and specificity, associated with an environmentally friendly and robust design. Also, the proposed design withstands several cycles of regeneration, a feature absent in paper-SERS immunoassays and this opens the way for sensitive multiplexing applications on a microfluidic platform.
UR - http://www.scopus.com/inward/record.url?scp=85115642935&partnerID=8YFLogxK
U2 - 10.1039/d1tb01404h
DO - 10.1039/d1tb01404h
M3 - Article
C2 - 34551048
AN - SCOPUS:85115642935
SN - 2050-750X
VL - 9
SP - 7516
EP - 7529
JO - Journal of Materials Chemistry B
JF - Journal of Materials Chemistry B
IS - 36
ER -