Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting
Liquid-borne particles sampling and cantilever-based mass detection are widely applied in many industrial and scientific fields e.g., in the detection of physical, chemical, and biological particles, and disease diagnostics, etc. Microscopic analysis of particles-adsorbed cantilever-samples can prov...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-04-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/20/9/2508 |
| _version_ | 1827717773541769216 |
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| author | Wilson Ombati Nyang’au Andi Setiono Angelika Schmidt Harald Bosse Erwin Peiner |
| author_facet | Wilson Ombati Nyang’au Andi Setiono Angelika Schmidt Harald Bosse Erwin Peiner |
| author_sort | Wilson Ombati Nyang’au |
| collection | DOAJ |
| description | Liquid-borne particles sampling and cantilever-based mass detection are widely applied in many industrial and scientific fields e.g., in the detection of physical, chemical, and biological particles, and disease diagnostics, etc. Microscopic analysis of particles-adsorbed cantilever-samples can provide a good basis for measurement comparison. However, when a particles-laden droplet on a solid surface is vaporized, a cluster-ring deposit is often yielded which makes particles counting difficult or impractical. Nevertheless, in this study, we present an approach, i.e., on-cantilever particles imprinting, which effectively defies such odds to sample and deposit countable single particles on a sensing surface. Initially, we designed and fabricated a triangular microcantilever sensor whose mass <i>m</i><sub>0</sub>, total beam-length <i>L</i>, and clamped-end beam-width <i>w</i> are equivalent to that of a rectangular/normal cantilever but with a higher resonant frequency (271 kHz), enhanced sensitivity (0.13 Hz/pg), and quality factor (~3000). To imprint particles on these cantilever sensors, various calibrated stainless steel dispensing tips were utilized to pioneer this study by dipping and retracting each tip from a small particle-laden droplet (resting on a hydrophobic <i>n</i>-type silicon substrate), followed by tip-sensor-contact (at a target point on the sensing area) to detach the solution (from the tip) and adsorb the particles, and ultimately determine the particles mass concentration. Upon imprinting/adsorbing the particles on the sensor, resonant frequency response measurements were made to determine the mass (or number of particles). A minimum detectable mass of ~0.05 pg was demonstrated. To further validate and compare such results, cantilever samples (containing adsorbed particles) were imaged by scanning electron microscopy (SEM) to determine the number of particles through counting (from which, the lowest count of about 11 magnetic polystyrene particles was obtained). The practicality of particle counting was essentially due to monolayer particle arrangement on the sensing surface. Moreover, in this work, the main measurement process influences are also explicitly examined. |
| first_indexed | 2024-03-10T20:10:09Z |
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| id | doaj.art-112d48c0536c4749b9cbff10a227aa5e |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T20:10:09Z |
| publishDate | 2020-04-01 |
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| series | Sensors |
| spelling | doaj.art-112d48c0536c4749b9cbff10a227aa5e2023-11-19T22:59:02ZengMDPI AGSensors1424-82202020-04-01209250810.3390/s20092508Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever ImprintingWilson Ombati Nyang’au0Andi Setiono1Angelika Schmidt2Harald Bosse3Erwin Peiner4Institute of Semiconductor Technology (IHT) and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, D38106 Braunschweig, GermanyInstitute of Semiconductor Technology (IHT) and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, D38106 Braunschweig, GermanyInstitute of Semiconductor Technology (IHT) and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, D38106 Braunschweig, GermanyPrecision Engineering Division, Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, GermanyInstitute of Semiconductor Technology (IHT) and Laboratory for Emerging Nanometrology (LENA), Technische Universität Braunschweig, D38106 Braunschweig, GermanyLiquid-borne particles sampling and cantilever-based mass detection are widely applied in many industrial and scientific fields e.g., in the detection of physical, chemical, and biological particles, and disease diagnostics, etc. Microscopic analysis of particles-adsorbed cantilever-samples can provide a good basis for measurement comparison. However, when a particles-laden droplet on a solid surface is vaporized, a cluster-ring deposit is often yielded which makes particles counting difficult or impractical. Nevertheless, in this study, we present an approach, i.e., on-cantilever particles imprinting, which effectively defies such odds to sample and deposit countable single particles on a sensing surface. Initially, we designed and fabricated a triangular microcantilever sensor whose mass <i>m</i><sub>0</sub>, total beam-length <i>L</i>, and clamped-end beam-width <i>w</i> are equivalent to that of a rectangular/normal cantilever but with a higher resonant frequency (271 kHz), enhanced sensitivity (0.13 Hz/pg), and quality factor (~3000). To imprint particles on these cantilever sensors, various calibrated stainless steel dispensing tips were utilized to pioneer this study by dipping and retracting each tip from a small particle-laden droplet (resting on a hydrophobic <i>n</i>-type silicon substrate), followed by tip-sensor-contact (at a target point on the sensing area) to detach the solution (from the tip) and adsorb the particles, and ultimately determine the particles mass concentration. Upon imprinting/adsorbing the particles on the sensor, resonant frequency response measurements were made to determine the mass (or number of particles). A minimum detectable mass of ~0.05 pg was demonstrated. To further validate and compare such results, cantilever samples (containing adsorbed particles) were imaged by scanning electron microscopy (SEM) to determine the number of particles through counting (from which, the lowest count of about 11 magnetic polystyrene particles was obtained). The practicality of particle counting was essentially due to monolayer particle arrangement on the sensing surface. Moreover, in this work, the main measurement process influences are also explicitly examined.https://www.mdpi.com/1424-8220/20/9/2508piezoresistive microcantilever mass sensorresonant frequencydispensing tipdropletparticle samplingadsorption |
| spellingShingle | Wilson Ombati Nyang’au Andi Setiono Angelika Schmidt Harald Bosse Erwin Peiner Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting Sensors piezoresistive microcantilever mass sensor resonant frequency dispensing tip droplet particle sampling adsorption |
| title | Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting |
| title_full | Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting |
| title_fullStr | Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting |
| title_full_unstemmed | Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting |
| title_short | Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting |
| title_sort | sampling and mass detection of a countable number of microparticles using on cantilever imprinting |
| topic | piezoresistive microcantilever mass sensor resonant frequency dispensing tip droplet particle sampling adsorption |
| url | https://www.mdpi.com/1424-8220/20/9/2508 |
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