Strip Sensors Research Articles

Turn-off luminescence sensing, white light emission and magnetic studies of two-dimensional lanthanide MOFs.

The lanthanide metal organic framework compounds [Ln(BPTA)1.5(Bpy)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1a-5a) and [Ln(BPTA)1.5(Phen)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1b-5b) were prepared by employing 2,5-bis(prop-2-yn-1-yloxy)terephthalic acid (2,5-BPTA) as the primary ligand and 2,2'-bipyridine (1a-5a) and 1,10-phenanthroline (1b-5b) as the secondary ligands. Single-crystal structural studies on [Gd(BPTA)1.5(Bpy)]·0.5DMF (3a) and [Dy(BPTA)1.5(Phen)]·0.5DMF (5b) indicated that the compounds have a two-dimensional structure. The Y compound exhibits blue emission, and the other compounds exhibit emission in the expected regions (λex = 350 nm). White light emission was achieved by careful mixing of the red (Eu3+) and green (Tb3+) components in the blue emitting Y compound. Thus, Y0.96Tb0.02Eu0.02 (bpy) and Y0.939Tb0.06Eu0.001 (phen) were found to show white emission when excited using a wavelength of 350 nm. The introduction of N-N-containing ancillary ligands (i.e., bpy and phen) increased the overall quantum yield (QY) of white light emission to 31% and 43%, respectively. The high QY observed for the Tb and Eu compounds was found to be sensitive and selective for the fluorometric detection of azinphos-methyl pesticide and trinitrophenol (TNP) in an aqueous medium at the ppb level. The same behaviour was observed when utilising the compounds as onsite paper strip sensors. Their magnetic properties were also studied, revealing for the Tb and Dy derivatives slow relaxation of the magnetisation at low temperature. The present study highlights the usefulness of rigid π-conjugated molecules such as 2,2'-bipyridine and 1,10-phenanthroline in enhancing the many utilities of rare-earth-containing MOFs towards white light emission, the sensing of harmful and dangerous substances and magnetic properties.

Optimization of low-noise read-out electronics for high energy resolution X-ray strip detectors

Semiconductor strip sensors applied as solid-state radiation or particle detectors can be used in radiation detection and measurement for various applications in particle physics experiments, X-ray imaging (e.g. medical), or material science. The X-ray imaging devices with spectroscopic and position resolution features are a very important research topic at many institutes and companies worldwide. Short strip silicon detectors are good candidates for X-ray spectroscopy, because of their relatively small capacitance and leakage current. If additionally, strip pitch is below 100 μm, then the high spatial resolution is also possible. In this paper, the analysis and noise optimization of the read-out electronics for short silicon strip detectors with Charge Sensitive Amplifier (CSA) and shaping amplifier (shaper) is presented. The CSA is optimized for the detector capacitance of around 1.5 pF, and the shaper nominal peaking time is about 1 μs (controlled by the sets of switches). We take into account the sources of noise in a radiation imaging system (current parallel noise, voltage series noise, and 1/f or flicker series noise) both internal (related to the front-end electronics itself) but also external, stemming from a sensor, interconnect, or printed circuit board parasitic components. We target the noise level below 40 el. rms, considering low power consumption (a few mW) and limited channel area.

Fluorescent strip sensor for rapid and ultrasensitive determination of fluoroquinolones in fish and milk.

The synthetic antibiotics fluoroquinolones are popular due to their good antibacterial performance and low price, but the risk to human health caused by their residues has attracted great attention. In this study, an ultra-sensitive mAb, 4D7, was prepared with an IC50 of 0.027 ng mL-1 to norfloxacin (NOR) and cross-reactivity of 19.7-47.7% to lomefloxacin (LOM), pefloxacin (PEF), ofloxacin (OFL), enrofloxacin (ENR), ciprofloxacin (CIP), and danofloxacin (DAN). Based on mAb 4D7 and Eu-fluorescent microspheres, a rapid and sensitive immunochromatographic strip was developed for the detection of fluoroquinolone residues in fish and milk. The detection ranges (IC20-IC80) of the strip for the detection of NOR, PEF, LOM, OFL, ENR, CIP and DAN were 0.19-1.1 μg kg-1, 0.39-2.1 μg kg-1, 0.5-2.6 μg kg-1, 0.43-3.3 μg kg-1, 0.61-3.5 μg kg-1, 0.69-5.5 μg kg-1, 0.52-3.4 μg kg-1 in fish, and 0.027-0.19 μg kg-1, 0.049-0.34 μg kg-1, 0.069-0.39 μg kg-1, 0.06-0.41 μg kg-1, 0.089-0.65 μg kg-1, 0.12-0.81 μg kg-1, 0.091-0.52 μg kg-1 in milk, respectively. The recovery rates in spiked sample tests were 88.6-113.6% with a coefficient of variation less than 8.4%. Thus the newly-developed strip was sensitive and reliable for rapid on-site detection of fluoroquinolone residues in fish and milk.

Performance characterization and radiation tolerance evaluation of the SSA2 ASIC, the strip sensor readout ASIC of the CMS Outer Tracker at the HL-LHC

This contribution presents the results of the performance characterization and radiation tolerance evaluation of the SSA2 ASIC, the short-strip readout ASIC for the CMS Outer-Tracker PS-module. The ASIC performance is characterised by different temperatures and operating conditions, at the die level as well as at the wafer level. The radiation evaluation comprises Total-Ionising-Dose (TID) tests and Single-Event-Effects (SEEs). Wafer-level testing provided a large dataset to evaluate the production yield. The presented test results are in agreement with the design simulations and are well within the application requirements for operation in the CMS outer-tracker at the HL-LHC.

A QR code-integrated chromogenic paper strip for detection of hydrogen peroxide in aqueous samples.

Hydrogen peroxide (H2O2) is commonly used as a preservative, disinfectant, bleach, and oxidizing agent. The prolonged consumption of H2O2 adulterated milk is harmful to human health when consumed in the diet. Exposure to H2O2 can lead to oxidative stress, cell damage and tissue injury. Due to the potential adverse effects, the use of hydrogen peroxide is regulated in certain applications, such as in food, water treatment plants and medical products. Several methods are available for the detection of H2O2 in various matrices. Here, a method and QR code-integrated chromogenic paper strip for the detection of H2O2 in aqueous samples has been developed. The spectrophotometric method showed an LOD and LOQ of 0.00087 ± 8.70 ×10-5% (v/v) and 0.0037 ± 0.0003% (v/v), respectively. The paper-based chromogenic strip prepared by immobilizing recognition solution onto a QR code was able to detect 0.0005% v/v of H2O2 in aqueous samples. The QR integrated chromogenic paper strip sensors can serve as a useful tool for consumers, regulatory agencies, and the food industry to assess food quality and authenticity.

A 64 channels ASIC for the readout of the silicon strip detectors of the PANDA micro-vertex detector

The ToASt ASIC is a 64 channel integrated circuit designed for the readout of the double-sided silicon strip sensors that will equip the micro-vertex detector of the PANDA experiment. The ToASt ASIC operates with a 160 MHz clock, which defines also the time resolution. A common time stamp is distributed to all channels to provide a common time reference for time of arrival and time over threshold measurements. Two 160 Mb/s serial lines provide the interface to the data concentrator. ToASt is implemented in a commercial 110 nm CMOS technology with triplicated logic to protect against single event upsets.

Evaluation of dry stored disposable sensor strip on rapid SARS-CoV-2 detection platform

This study investigated a SARS-CoV-2 virus detection mechanism using dry-stored disposable strips. The accuracy of this sensing platform is as good as polymerase chain reaction (PCR) with a detection time of fewer than 30 s. SARS-CoV-2 antibodies were biofunctionalized on disposable strips similar to glucose detection strips to detect the presence and concentrations of SARS-CoV-2 in saliva samples. Eight 1 ms electric pulses were sent through the sensor strip with a saliva sample in its microfluidic chamber. A circuit board embedded with MOSFET was also employed to amplify the detected signals and convert the signal to digital readings displayed on an LCD screen. The COV-antibody functionalized disposable strips were stored in a dry condition for at least one day before analyzing clinical human saliva samples with known cycling threshold (Ct) values confirmed with conventional PCR tests. Results demonstrate our system is capable of showing qualitative positive or negative results within 30 s and providing quantitative SARS-CoV-2 concentrations in terms of Ct values in 5 min.

Sensor strips provide SARS-CoV-2 detection in 30 seconds

Dry-stored disposable strips use biofunctionalized antibodies and show promise for rapid testing large crowds for events.

A paper-based lateral flow strip assay based on enzyme-mediated pectin viscosity change for the determination of polygalacturonase activity

In this study, a simple, convenient, and cost-effective paper-based lateral flow strip sensor combined with a smartphone was developed for the determination of polygalacturonase (PG) activity based on the modulation of viscosity of pectin solution, which can be visualized by the difference in the average diffusion distance on the pH indicator strips. Effects of the pectin concentration, enzymatic reaction time, the volume of diffusion liquid, and the diffusion time on the average diffusion distance were systematically investigated. For quantitative analysis of PG activity, the images of the pH indicator strips after lateral flow diffusion were collected by a smartphone and processed through Adobe Photoshop CS 5.1 software. Under the optimal conditions, the average lateral flow diffusion distance shows a good linear relationship with PG activity in the range of 0.025–0.80 U/mL, and the limit of quantification is 0.025 U/mL. Finally, the applicability of the proposed strategy was successfully verified by measuring PG activity in cucumber sample. The recoveries are in the range of 87.4%–96.7%. In short, the present study developed a convenient, low-cost, and accurate approach for on-site detecting of PG activity, especially in remote or resource-limited regions.

ATLAS ITk strip sensor quality control procedures and testing site qualification

The high-luminosity upgrade of the Large Hadron Collider, scheduled to become operational in 2029, requires the replacement of the ATLAS Inner Detector with a new all-silicon Inner Tracker. Radiation hard n+-in-p micro-strip silicon sensors were developed by the ATLAS Inner Tracker strip collaboration and are produced by Hamamatsu Photonics K.K. Production of the total amount of 22000 strip sensors has started in 2020 and will continue until 2025. The ATLAS strip sensor collaboration has the responsibility to monitor the quality of the fabricated devices by performing detailed measurements of individual sensor characteristics and by comparing the obtained results with the tests done by the manufacturer. Dedicated Quality Control procedures were developed to check whether the delivered large-format sensors adhere to the ATLAS specifications. The institutes performing the Quality Control testing of the pre-production and production ATLAS ITk strip sensors had to initially be qualified for multiple high-throughput tests by successfully completing the Site Qualification process. The Quality Control procedures and the qualification process are described in this paper.

Silica–silver core–shell nanoparticles incorporated with cellulose filter paper as an effective colorimetric probe for mercury ion detection in aqueous media: Experimental and computational evaluations

This study investigates the facile and rapid detection of mercury ions using silica–silver core–shell nanoparticles (SiO2–AgNPs) incorporating a paper-based colorimetric sensor strip. A strong surface plasmon resonance peak at λ = 430 nm was observed for the resultant SiO2–AgNPs. The attachment of the AgNPs to the surface of SiO2 and the deposition of the AgNPs on the paper strip were confirmed using an electron microscope. The sensing of the SiO2–AgNPs toward the mercuric ion (Hg2+) in an aqueous solution indicated a rapid response in terms of a color change from yellowish-brown to colorless with a response time of 5–10 s. The prepared SiO2–AgNPs deposited on the paper strip exhibited high selectivity toward Hg2+ compared with other metal ions. The limit of detection for this assay was 1.13 nM, with an excellent correlation value of R2 = 0.9936. In addition, the complexation mode of the SiO2–AgNPs with Hg2+ was also elucidated via theoretical calculations using the density functional theory approach. This approach also provides insight into the complexation structure in terms of the electronic alteration of the SiO2–AgNPs prior to and following their interaction with Hg2+. Overall, the study demonstrates that SiO2–AgNP-based sensor materials can be utilized for the selective recognition of Hg2+ in aqueous solutions.

Vibration analysis of a porous hollow conical rotor with circumferentially distributed piezoceramic strips

The present study investigates vibrational behavior of a porous conical hollow rotor. Inner and outer rotor surface, sensor, and actuator strips made of piezoceramic are modeled and positioned, which are symmetrically distributed in the circumferential direction. Kinetic and potential energies were computed considering the effects of Coriolis and centrifugal force. Modeling of the system has been carried out assuming classical theory and using Lagrange approach for simple-supported boundary conditions. Also, the relations of piezoceramic and three types of porosity attend in equilibrium equations. The discretization of kinetic and potential energies using displacement field which is defined as double mixed series based on independent mode shape and time function leads to obtaining the equations in form of ordinary differential. To calculate the natural frequencies, the equations were converted to a special form of state space model. The correctness of the study is examined by comparing it with similar study results. The most consequential parameters affecting the forward and backward natural frequency, such as type and porosity coefficient, size, number, and thickness of piezoceramic, and the rotor angular velocity, are researched. The results demonstrate that the effect of porosity coefficient in various longitudinal modes on natural frequency is different.

Green synthesis of silver nanoparticles using the extract of spent coffee used for paper-based hydrogen peroxide sensing device

Hydrogen peroxide (H2O2) has attracted considerable attention for use as a disinfectant ingredient for various applications over the decades. The use of H2O2 within the safety regulations can avoid its toxicity to human health and the environment. In this study, a paper-based sensor containing green-synthesized silver nanoparticles (P-AgNPs) was developed for use in a smartphone in the determination of the H2O2 concentration. In the synthesis process, an extract of spent coffee grounds was used as a bioreducing agent. The effects of reaction time and silver nitrate (AgNO3) concentration on the green synthesis of silver nanoparticles (AgNPs) were investigated. The optimum conditions for the preparation of P-AgNPs were determined to be 100 mM AgNO3 (P-AgNPs-100) and 15 h synthesis time. The P-AgNPs-100 sensor exhibited high sensitivity with a detection limit of 1.26 mM H2O2, which might be suitable for the detection of H2O2-based household and beverage sanitizers. The H2O2 detection capability of P-AgNPs-100 was comparable to that of a commercial strip sensor. Furthermore, P-AgNPs-100 had a detection efficiency of more than 95% after long-term storage for 100 days.

Disposable screen-printed electrochemical sensing strips for rapid decentralized measurements of salivary ketone bodies: Towards therapeutic and wellness applications

The interest in ketone bodies (KBs) has intensified recently as they play significant roles in healthcare, nutrition, and wellness applications. We present a disposable electrochemical sensing strip for rapid decentralized detection of β-hydroxybutyrate (HB), one of the dominant physiological KBs, in saliva. The new salivary enzymatic HB sensor strip relies on a gold-coated screen-printed carbon electrode modified with a reagent layer containing toluidine blue O (TBO mediator), β-hydroxybutyrate dehydrogenase (HBD enzyme), and the HBD cofactor nicotinamide adenine dinucleotide (NAD+ coenzyme), along with carbon nanotubes (CNTs) and chitosan (Chit) for enhancing the sensor's sensitivity and for encapsulating the enzyme and its cofactor, respectively. The systematic optimization resulted in an attractive analytical performance, with a rapid response time within 60 s, a wide HB dynamic detection range from 0.1 to 3.0 mM along with a low limit of detection (50 μM HB) in an artificial saliva medium. The strip displays high selectivity for HB over acetoacetate (AcAc) and other interferences (i.e., acetaminophen, ascorbic acid, glucose, lactic acid, and uric acid), good reproducibility, and high stability towards temperature or pH effects. The new disposable sensing strip system, coupled with a hand-held electrochemical analyzer, showed rapid HB monitoring in human saliva samples collected from healthy volunteers, with similar temporal profiles to those obtained in parallel capillary blood measurements in response to the intake of keto supplements. This strip enables efficient, reliable, and near real-time salivary HB detection to track non-invasively the dynamics of HB concentrations after intaking commercial supplements towards diverse healthcare and nutrition applications.

Effect of irradiation and annealing performed with bias voltage applied across the coupling capacitors on the interstrip resistance of ATLAS ITk silicon strip sensors

The powering configuration of the silicon strip modules developed for the new Inner Tracker of the ATLAS experiment includes a voltage of up to 0.5 V across the coupling capacitor of each individual strip. However, this voltage is usually not applied in the sensor irradiation studies due to the significant technical and logistical complications. To study the effect of an irradiation and a subsequent beneficial annealing on the strip sensors in real experimental conditions, four prototype ATLAS17LS miniature sensors were irradiated by 60Co source and annealed, both with and without the bias voltage of 0.5 V applied across the coupling capacitors. The values of interstrip resistance measured on irradiated samples before and after annealing indicate that increase of radiation damage caused by the applied voltage can be compensated by the presence of this voltage during annealing.

4D nanoprinted sensor for facile organo-arsenic detection: A two-photon lithography-based approach

Engineered 3Dnanostructures have played a crucial role in the development of modern electronic devices. However, the demand for higher dimensional nanostructures have become a necessity for the development of superior next generation miniaturized devices. Traditional two-photon femtosecond laser-based fabrication techniques have enabled fabrication of 3D nanostructures. Carbon quantum dots have recently emerged as a new alternative for achieving subwavelength 3D optical lithography. Here, we report sensing of organo-arsenic(V) species at ppb levels using multimodal carbon quantum dots based 4D miniaturized ultrasensitive nanosensor and development of a device thereof using two-photon lithography. Manganese, nitrogen, and sulphur-doped carbon quantum dots have been used for development of this two-component, two-photon active functional resin for 3D printing of optically active 4D nanostructures. These have sub-wavelength resolved features, and are selectively sensitive to organo-arsenic species. The doped-carbon quantum dots initiate two-photon polymerization in the functional resin and induce emissive attributes to the polymerized nanostructures that impart selectivity towards dimethylarsinate ions (DAI) even at the ppb concentration levels. The miniaturized sensor strip shows a change in fluorescence of the nanostructures when subjected to the analyte. The emission intensities increases with increase in the concentration of DAI. The sensor can detect concentrations of the analyte as low as 1 ppb. This work opens new avenues to meet the demand for multi-dimensional nanostructures for development of superior next-generation of multifunctional miniaturized devices.

Pre-production results from ATLAS ITk Strip Sensors Quality Assurance Testchip

The production of strip sensors within the framework of the ATLAS Inner Tracker (ITk) development is a process which requires continuous evaluation during the full production period (about 4 years). Such an evaluation is divided into two different parts: Quality Control (QC), which focuses on the final product (the actual sensors) and tries to identify possible defects once the fabrication is completed, and Quality Assurance (QA), which aims to prevent deviations in the manufacturing process and uses specifically-designed test structures. The initial sensor pre-production consists of 5% (1041 sensors) of the total number of sensors expected during production. As part of pre-production, the collaboration has measured key parameters from miniature strip sensors (minis), monitor diodes (MD8), and the ATLAS Testchip, before and after irradiation. In this contribution we focus on the analysis of the results of the MD8 and the Testchip. All parameters have been obtained from the test structures (MD8, bias resistors, interdigitated structures, field oxide capacitors, coupling capacitors, punch-through protection structures and cross-bridge resistors) measured at the different test sites (KEK/Tsukuba, Birmingham, Toronto, Ljubljana, Valencia, Carleton, Prague, CNM-Barcelona). The results are compared to predefined pre- and post-irradiation specifications for each tested parameter.

Monitoring therapeutic proton beams with LGAD silicon detectors

The University and the National Institute for Nuclear Physics of Torino are developing LGAD-based prototypes for beam monitoring in proton therapy. The direct measurement of single beam particles could overcome some features of currently used ionization chambers, such as slow charge collection and reduced sensitivity, which limit the implementation of advanced delivery techniques (e.g. rescanning). LGAD strip sensors have been designed and produced by Bruno Kessler Foundation (FBK, Trento) specifically for this project. A counter prototype to directly count individual protons at clinical fluence rates (106–1010 protons/cm2·s) and a telescope system to measure the beam energy with time-of-flight (TOF) techniques are described. Tests of LGAD silicon strip sensors performed on synchrotron and cyclotron beams of therapeutic centers, using a pin-hole ionization chamber for the independent measurement of the particle flux, already showed the possibility to keep the counting error <1% up to a beam fluence rate of few 108 protons/cm2·s. The ongoing tests of counting sensors readout by a dedicated fast charge sensitive amplifier chip are reported. The telescope system, made of two sensors at a distance up to 95 cm, allows measuring the beam energy in the clinical range (70–230 MeV) with a maximum deviation of 310 keV in respect to the nominal one, with an uncertainty of 500 keV, thus achieving the prescribed clinical accuracy of 1 mm in the range in water.

Characterization of passive CMOS sensors with RD53A pixel modules

Both the current upgrades to accelerator-based HEP detectors (e.g. ATLAS, CMS) and also future projects (e.g. CEPC, FCC) feature large-area silicon-based tracking detectors. We are investigating the feasibility of using CMOS foundries to fabricate silicon radiation detectors, both for pixels and for large-area strip sensors. A successful proof of concept would open the market potential of CMOS foundries to the HEP community, which would be most beneficial in terms of availability, throughput and cost. In addition, the availability of multi-layer routing of signals will provide the freedom to optimize the sensor geometry and the performance, with biasing structures implemented in poly-silicon layers and MIM-capacitors allowing for AC coupling. A prototyping production of strip test structures and RD53A compatible pixel sensors was recently completed at LFoundry in a 150nm CMOS process. This presentation will focus on the characterization of pixel modules, studying the performance in terms of charge collection, position resolution and hit efficiency with measurements performed in the laboratory and with beam tests. We will report on the investigation of RD53A modules with 25x100 μm2 cell geometry.

Performance and running experience of the Belle II silicon vertex detector

The Belle II silicon vertex detector is one of the vertex detectors in the Belle II experiment. The detector reads out the signals from the double-sided silicon strip sensors with the APV25 front-end readout ASIC, adopting the chip-on-sensor concept to minimize the strip noise. The detector has been operated in the experiment since the spring of 2019. Analyzing the acquired data during the beam collisions, the excellent performance of the detector is confirmed. Also, the radiation dose and 1-MeV equivalent neutron fluence of the detector are estimated using the measured dose rates of the diamond sensors installed on the beam pipe and are compared with the measured radiation effects in the strip noise, leakage current, and depletion voltage. This paper briefly introduces the main features of the silicon vertex detector, and then reports on the measured performance and radiation effects of the first two years of running experience of the detector.