1
|
Di Franco C, Piscitelli M, Macchia E, Scandurra C, Catacchio M, Torsi L, Scamarcio G. Kelvin probe force microscopy on patterned large-area biofunctionalized surfaces: a reliable ultrasensitive platform for biomarker detection. JOURNAL OF MATERIALS CHEMISTRY. C 2023; 12:73-79. [PMID: 38143451 PMCID: PMC10734678 DOI: 10.1039/d3tc03110a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/18/2023] [Indexed: 12/26/2023]
Abstract
Kelvin probe force microscopy (KPFM) allows the detection of single binding events between immunoglobulins (IgM, IgG) and their cognate antibodies (anti-IgM, anti-IgG). Here an insight into the reliability and robustness of the methodology is provided. Our method is based on imaging the surface potential shift occurring on a dense layer of ∼5 × 107 antibodies physisorbed on a 50 μm × 90 μm area when assayed with increasing concentrations of antigens in phosphate buffer saline (PBS) standard solutions, in air and at a fixed scanning location. A comprehensive investigation of the influence of the main experimental parameters that may interfere with the outcomes of KPFM immune-assay is provided, showing the robustness and reliability of our approach. The data are supported also by a thorough polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) analysis of the physisorbed biolayer, in the spectral region of the amide I, amide II and amide A bands. Our findings demonstrate that a 10 min incubation in 500 μL PBS encompassing ≈ 30 antigens (100 zM) triggers an extended surface potential shift that involves the whole investigated area. Such a shift quickly saturates at increasing ligand concentration, showing that the developed sensing platform works as an OFF/ON detector, capable of assessing the presence of a few specific biomarkers in a given assay volume. The reliability of the developed methodology KPFM is an important asset in single molecule detections at a wide electrode interface.
Collapse
Affiliation(s)
- Cinzia Di Franco
- CNR - Institute of Photonics and Nanotechnologies, Via Amendola 173 70126 Bari Italy
| | - Matteo Piscitelli
- CNR - Institute of Photonics and Nanotechnologies, Via Amendola 173 70126 Bari Italy
- Dipartimento Interateneo di Fisica ''M. Merlin'', Università degli Studi di Bari Aldo Moro 70126 Bari Italy
| | - Eleonora Macchia
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro 70126 Bari Italy
- The Faculty of Science and Engineering, Åbo Akademi University 20500 Turku Finland
| | - Cecilia Scandurra
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4 70125 Bari Italy
| | - Michele Catacchio
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4 70125 Bari Italy
| | - Luisa Torsi
- Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4 70125 Bari Italy
| | - Gaetano Scamarcio
- CNR - Institute of Photonics and Nanotechnologies, Via Amendola 173 70126 Bari Italy
- Dipartimento Interateneo di Fisica ''M. Merlin'', Università degli Studi di Bari Aldo Moro 70126 Bari Italy
| |
Collapse
|
2
|
Yang X, Cui F, Guo X, Li D. Effects of nanosized titanium dioxide on the physicochemical stability of activated sludge flocs using the thermodynamic approach and Kelvin probe force microscopy. WATER RESEARCH 2013; 47:3947-3958. [PMID: 23706860 DOI: 10.1016/j.watres.2013.01.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 11/08/2012] [Accepted: 01/19/2013] [Indexed: 06/02/2023]
Abstract
The wide application of nanosized titanium dioxide (nano-TiO2) will result in high concentrations of the molecule in the aquatic environment, especially in the influent of wastewater treatment plants. The present study focuses on the potential effect of nano-TiO2 on the physicochemical stability of activated sludge flocs after long-term exposure, on which limited information is currently available. Kelvin probe force microscopy (KPFM) was innovatively applied to assess the surface potential of the activated sludge in situ. The physicochemical characteristics of the bioflocs with and without long-term exposure to nano-TiO2 were well elucidated by the thermodynamic approach. The results showed that the repulsive force predominated the bioflocs system as the concentration of nano-TiO2 increased, owing to the corresponding increase in the density of the negative charge. The bioflocs exposed to 100 ppm nano-TiO2 presented the strongest stability compared to the other two samples with low concentrations of nano-TiO2, which also indicated that the bioflocs with long-term exposure to nano-TiO2 had a low settlement efficiency of the corresponding activated sludge. Further, the extended Derjaugin, Landau, Verwey, and Overbeek (XDLVO) theory was used to explore the flocculation stability of the bioflocs system. As the concentration of nano-TiO2 increased, the ΔGiwi(LW)attraction (the van der Waals interaction) and the effective Hamaker constant decreased, the ΔGiwi(EL)(the electrostatic double-layers interaction) increasingly contributed to the interfacial repulsion, the ΔGiwi(AB)(the Lewis acid-base interaction) also exhibited a repulsive contribution to the total interaction energy and the ΔGiwi(TOT) (the total free energy of interaction) exhibited a repulsive contribution. These results are the keys for interpreting the adverse effects of nano-TiO2 on the activated sludge flocs of wastewater treatment plant (WWTP).
Collapse
Affiliation(s)
- Xiaonan Yang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
| | | | | | | |
Collapse
|
3
|
Hall A, Mundell VJ, Blanco-Andujar C, Bencsik M, McHale G, Newton MI, Cave GWV. Towards MRI microarrays. Chem Commun (Camb) 2010; 46:2420-2. [DOI: 10.1039/b925020d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
4
|
Rezende CA, Gouveia RF, da Silva MA, Galembeck F. Detection of charge distributions in insulator surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:263002. [PMID: 21828448 DOI: 10.1088/0953-8984/21/26/263002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Charge distribution in insulators has received considerable attention but still poses great scientific challenges, largely due to a current lack of firm knowledge about the nature and speciation of charges. Recent studies using analytical microscopies have shown that insulators contain domains with excess fixed ions forming various kinds of potential distribution patterns, which are also imaged by potential mapping using scanning electric probe microscopy. Results from the authors' laboratory show that solid insulators are seldom electroneutral, as opposed to a widespread current assumption. Excess charges can derive from a host of charging mechanisms: excess local ion concentration, radiochemical and tribochemical reactions added to the partition of hydroxonium and hydronium ions derived from atmospheric water. The last factor has been largely overlooked in the literature, but recent experimental evidence suggests that it plays a decisive role in insulator charging. Progress along this line is expected to help solve problems related to unwanted electrostatic discharges, while creating new possibilities for energy storage and handling as well as new electrostatic devices.
Collapse
Affiliation(s)
- C A Rezende
- Institute of Chemistry, University of Campinas-UNICAMP, PO Box 6154, CEP 13083-970, Campinas-SP, Brazil
| | | | | | | |
Collapse
|
5
|
Hong Q, Rogero C, Lakey JH, Connolly BA, Houlton A, Horrocks BR. Immobilisation of proteins at silicon surfaces using undecenylaldehyde: demonstration of the retention of protein functionality and detection strategies. Analyst 2009; 134:593-601. [DOI: 10.1039/b813328j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
6
|
Sinensky AK, Belcher AM. Label-free and high-resolution protein/DNA nanoarray analysis using Kelvin probe force microscopy. NATURE NANOTECHNOLOGY 2007; 2:653-9. [PMID: 18654392 DOI: 10.1038/nnano.2007.293] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 08/14/2007] [Indexed: 05/14/2023]
Abstract
Using the scanning probe technique known as Kelvin probe force microscopy it is possible to successfully devise a sensor for charged biomolecules. The Kelvin probe force microscope is a tool for measuring local variations in surface potential across a substrate of interest. Because many biological molecules have a native state that includes the presence of charge centres (such as the negatively charged backbone of DNA), the formation of highly specific complexes between biomolecules will often be accompanied by local changes in charge density. By spatially resolving this variation in surface potential it is possible to measure the presence of a specific bound target biomolecule on a surface without the aid of special chemistries or any form of labelling. The Kelvin probe force microscope presented here is based on an atomic force microscopy nanoprobe offering high resolution (<10 nm), sensitivity (<50 nM) and speed (>1,100 microm s(-1)), and the ability to resolve as few as three nucleotide mismatches.
Collapse
Affiliation(s)
- Asher K Sinensky
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 16-244, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | |
Collapse
|
7
|
Cheran LE, Cheung S, Al Chawaf A, Ellis JS, Belsham DD, MacKay WA, Lovejoy D, Thompson M. Label-free detection of neuron–drug interactions using acoustic and Kelvin vibrational fields. Analyst 2007; 132:242-55. [PMID: 17325758 DOI: 10.1039/b615476j] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Kelvin and acoustic fields of high-frequency have been employed in the non-invasive investigation of immortalized hypothalamic neurons, in order to assess their response to different concentrations of specific drugs, toxins, a stress-reducing hormone and neurotrophic factors. In an analytical systems biology approach, this work constitutes a first study of living neuron cultures by scanning Kelvin nanoprobe (SKN) and thickness shear mode (TSM) acoustic wave techniques. N-38 hypothalamic mouse neurons were immobilized on the gold electrode of 9 MHz TSM acoustic wave devices and gold-coated slides for study by SKN. The neurons were exposed to the neurochemicals betaseron, forskolin, TCAP, and cerebrolysin. Signals were collected with the TSM in real-time mode, and with the SKN in scanning and real-time modes, as the drugs were applied at biologically significant concentrations. With the TSM, for all drugs, some frequency and resistance shifts were in the same direction, contrary to normal functioning for this type of instrument. Possible mechanisms are presented to explain this behaviour. An oscillatory signal with periodicity of approximately 2 min was observed for some neuron-coated surfaces, where the amplitude of these oscillations was altered upon application of certain neurotrophic factors. These two new techniques present novel and non-invasive electrodeless methods for detecting changes at the cellular level caused by a variety of neuroactive compounds, without killing or destroying the neurons.
Collapse
Affiliation(s)
- Larisa-Emilia Cheran
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Gouveia RF, Costa CAR, Galembeck F. Electrostatic Patterning of a Silica Surface: A New Model for Charge Build-Up on a Dielectric Solid. J Phys Chem B 2005; 109:4631-7. [PMID: 16851542 DOI: 10.1021/jp0457601] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The polarization of interdigitated gold electrodes mounted over a silica thin film formed by oxidation of a Si wafer produces reproducible electrostatic patterns with overall excess negative charge, as observed by scanning electric potential microscopy. Domain charge concentrations as high as 76 charge units per square micrometer are obtained when a 5 V difference is applied to the electrodes thus producing fields in the 10(6) V m(-1) range. These patterns vanish when the electrodes are short-circuited and grounded. Characteristic times for pattern formation and relaxation are in the order of 10 min. The results are consistent with a model based on the discharge of H(+) ions at the negative electrodes, leaving behind immobile surface-bound SiO(-) groups and thus showing that chemisorption phenomena are decisive for electrostatic charging of insulators.
Collapse
Affiliation(s)
- Rubia F Gouveia
- Institute of Chemistry, Universidade Estadual de Campinas-UNICAMP, P.O. Box 6154, CEP 13084-971, Campinas - SP, Brazil
| | | | | |
Collapse
|
9
|
Thompson M, Cheran LE, Zhang M, Chacko M, Huo H, Sadeghi S. Label-free detection of nucleic acid and protein microarrays by scanning Kelvin nanoprobe. Biosens Bioelectron 2005; 20:1471-81. [PMID: 15626600 DOI: 10.1016/j.bios.2004.06.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Revised: 06/10/2004] [Accepted: 06/15/2004] [Indexed: 10/26/2022]
Abstract
A high-resolution scanning Kelvin nanoprobe is introduced as an alternative technique to the conventional fluorescence and mass spectrometric detection methods currently employed in nucleic acid and protein microarray technology. The new instrument is capable of the highly sensitive discernment of surface biochemical events taking place at molecular level such as nucleic acid hybridization and antibody-antigen interaction. The method involves measurement of changes in work function and surface potential instigated by such interactions. Being a label-free and non-contact technique, the structure, spatial configuration, local properties or function of the molecular system under study are not affected, nor perturbed by intercalating dyes, a strong electric field or ionizing beam. Subsequent to scanning, the microarray can be examined by other alternative approaches. Nucleic acids and proteins have been printed in microarray format on slides with a gold film in place using gold-sulphur interactive chemistry. Hybridization of nucleic acids for complementary and mismatched configurations shows consistent and reproducible values of work function. Differentiation of single internal mismatches is demonstrated. Protein concentration and formation of antibody-antigen pairs can be visualized and examined with high sensitivity and good inter-spot reproducibility.
Collapse
Affiliation(s)
- Michael Thompson
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ont., Canada M5S 3H6.
| | | | | | | | | | | |
Collapse
|
10
|
Cheran LE, Sadeghi S, Thompson M. Scanning Kelvin nanoprobe detection in materials science and biochemical analysis. Analyst 2005; 130:1569-76. [PMID: 16284653 DOI: 10.1039/b509724j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Kelvin nanoprobe is an extremely sensitive instrument capable of discerning subtle molecular interactions using vibrating electromagnetic and acoustic fields. It is based on the measurement of a fundamental material property, the work function. Modulation of this substrate parameter is caused by the adsorption or desorption of molecules, oxidation, corrosion, contamination, mechanical stress, illumination, temperature changes, electrostatic charging, surface treatment, attached dipolar structures and/or the immobilization of biomolecules. The present article explains the general principles of the method and offers an indication of the wide range of possible applications, with an emphasis on potential use in the biotechnological arena.
Collapse
Affiliation(s)
- Larisa-Emilia Cheran
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6
| | | | | |
Collapse
|
11
|
Lassalle N, Mailley P, Vieil E, Livache T, Roget A, Correia J, Abrantes L. Electronically conductive polymer grafted with oligonucleotides as electrosensors of DNA. J Electroanal Chem (Lausanne) 2001. [DOI: 10.1016/s0022-0728(01)00537-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|