On-chip Isolation Research Articles

Magnetic Nanoparticle-Based Microfluidic Platform for Automated Enrichment of High-Purity Extracellular Vesicles.

Extracellular vesicles (EVs) are available in various biological fluids and have highly heterogeneous sizes, origins, contents, and functions. Rapid enrichment of high-purity EVs remains crucial for enhancing research on EVs in tumors. In this work, we present a magnetic nanoparticle-based microfluidic platform (ExoCPR) for on-chip isolation, purification, and mild recovery of EVs from cell culture supernatant and plasma within 29 min. The ExoCPR chip integrates bubble-driven micromixers and immiscible filtration assisted by surface tension (IFAST) technology. The bubble-driven micromixer enhances the mixing between immunomagnetic beads and EVs, eliminating the need for manual pipetting or off-chip oscillatory incubation. The high-purity EVs were obtained after passing through the immiscible phase interface where hydrophilic or hydrophobic impurities nonspecifically bound to SIMI were removed. The ExoCPR chip had a capture efficiency of 75.8% and a release efficiency of 62.7% for model EVs. We also demonstrated the powerful performance of the ExoCPR in isolating EVs from biological samples (>90% purity). This chip was further employed in clinical plasma samples and showed that the number of GPC3-positive EVs isolated from hepatocellular carcinoma patients was significantly higher than that of healthy individuals. This ExoCPR chip may provide a promising tool for EV-based liquid biopsy and other fundamental research.

Abstract 7485: Microfluidic detection of dual positive cells in whole blood of metastatic breast cancer patients

Abstract Background. Dual positive cells (DPCs) that express both epithelial markers and leukocytic markers have been observed in peripheral blood of breast cancer patients. DPCs acquire functional behaviors from both cell types which may drive tumor progression. However, the lack of reliable methods to isolate and identify DPCs has hindered the investigation of their origin and clinical implications in breast cancer patients. While microfluidic devices have been widely used for the detection of circulating tumor cells (CTCs) by liquid biopsy, DPC detection is underexplored in these devices. Herein, we demonstrate rapid onchip isolation and detection of DPCs in whole blood samples from metastatic breast cancer (MBC) patients using an integrated microfluidic device. Methods. Our microfluidic device consists of a unique preconditioning component that concentrates targets in whole blood and a downstream cell immobilization component that captures target cells. We included 7 female patients with MBC, of which 29% are white (2), 57% are African American (4), and 14% are Latina (1). The median age is 50y (34y -75y). All patients were undergoing systemic breast cancer therapy at the time of blood collection. A total of 9 samples (4 mL each) were collected from either an antecubital vein (peripheral vein) or the subcutaneous port catheter (central vein) of these patients. All samples were processed within 5 hours of blood drawn in our novel microfluidic biochip. CTCs (EpCAM+/CK+, CD45-, DAPI+) and DPCs (EpCAM+/CK+, CD45+/CD66b+, DAPI+) were identified by immunofluorescence after cells were fixed. Results. Processing of each sample was completed within 40 minutes using our microfluidic device. Both DPCs and CTCs were detected in all the samples (9/9). The average DPC count was 3 DPCs per 4 mL whole blood with a standard deviation of 1.9 cells. The average CTC count was 9 with a standard deviation of 5 per 4 mL whole blood. 89% of the samples (8/9) had > 5 CTCs after the sample volume is scaled to the standard 7.5 mL. No correlation was found between DPC count and CTC count (Pearson correlation coefficient r=0.08). While the blood collection location (central vs peripheral veins) had a significant impact on the CTC count (12.6 vs 4 on average with p<0.01), there was no statistical difference in DPC counts in the samples collected from central and peripheral veins. Conclusions. Both DPCs and CTCs can be rapidly isolated and detected from MBC patient whole blood in our microfluidic device. Our preliminary results indicate no correlation between DPCs and CTCs, suggesting that DPCs might not originate in blood circulation of MBC patients. More work with a larger patient cohort will be needed to further investigate the clinical implications of DPCs on MBC patients. Citation Format: Jian Zhou, Qiyue Luan, Celine Macaraniag, Arielle B. Guzman, Maria Mantice, Oana Danciu, Kent F. Hoskins, Ian Papautsky. Microfluidic detection of dual positive cells in whole blood of metastatic breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7485.

The integrated on-chip isolation and detection of circulating tumour cells.

Circulating tumour cells (CTCs) are cancer cells shed from a primary tumour which intravasate into the blood stream and have the potential to extravasate into distant tissues, seeding metastatic lesions. As such, they can offer important insight into cancer progression with their presence generally associated with a poor prognosis. The detection and enumeration of CTCs is, therefore, critical to guiding clinical decisions during treatment and providing information on disease state. CTC isolation has been investigated using a plethora of methodologies, of which immunomagnetic capture and microfluidic size-based filtration are the most impactful to date. However, the isolation and detection of CTCs from whole blood comes with many technical barriers, such as those presented by the phenotypic heterogeneity of cell surface markers, with morphological similarity to healthy blood cells, and their low relative abundance (∼1 CTC/1 billion blood cells). At present, the majority of reported methods dissociate CTC isolation from detection, a workflow which undoubtedly contributes to loss from an already sparse population. This review focuses on developments wherein isolation and detection have been integrated into a single-step, microfluidic configuration, reducing CTC loss, increasing throughput, and enabling an on-chip CTC analysis with minimal operator intervention. Particular attention is given to immune-affinity, microfluidic CTC isolation, coupled to optical, physical, and electrochemical CTC detection (quantitative or otherwise).

Functional surfaces for exosomes capturing and exosomal microRNAs analysis

Exosomes are small extracellular vesicles well-studied both as cell signaling elements and as source of highly informative biomarkers, in particular microRNAs. Standard techniques for exosome isolation are in general scarcely efficient and give low purity vesicles. New techniques combining microfluidics with suitable functionalized surfaces could overcome these disadvantages. Here, different functional surfaces aimed at exosomes capture are developed thank to the functionalization of silicon oxide substrates. Charged surfaces, both positive and negative, neutral and immunoaffinity surfaces are characterized and tested in functional assays with both exosome mimicking vesicles and exosomes purified from cell supernatants. The different surfaces showed promising properties, in particular the negatively-charged surface could capture more than 4 × 108 exosomes per square centimeter. The captured exosomes could be recovered and their biomarker cargo analyzed. Exosomal microRNAs were successfully analyzed with RT-PCR, confirming the good performances of the negatively-charged surface. The best-performing functionalization could be easily moved to microdevice surfaces for developing modular microfluidic systems for on-chip isolation of exosomes, to be integrated in simple and fast biosensors aimed at biomarker analysis both in clinical settings and in research.

Tunable, coherent optical comb source via on-chip bidirectional coupling.

A tunable comb source is demonstrated through gain switching on a three-sectioned photonic integrated circuit (PIC). The PIC consists of two mutually coupled lasers connected by a passive waveguide. One of these is a tunable, two-section, single mode laser. The second laser is a simple Fabry-Perot cavity laser which can be phase-locked with the single mode laser via bidirectional coupling. Frequency combs are produced by gain switching the Fabry-Perot laser by applying a high-power radio frequency signal. Combs are generated with line spacings ranging from 3.5 to 8 GHz. The on-chip bidirectional coupling causes the comb to also be generated in the two-section device. Despite the lack of on-chip optical isolation between the lasers, the resulting combs are stable. Numerical simulations using a delay-differential model reproduce the results and reveal the important role played by the short delay times inherent to on-chip integration in this stability.

Unidirectional microwave transduction with chirality selected short-wavelength magnon excitations

Nonreciprocal magnon propagation has recently become a highly potential approach of developing chip-embedded microwave isolators for advanced information processing. However, it is challenging to achieve large nonreciprocity in miniaturized magnetic thin-film devices because of the difficulty of distinguishing propagating surface spin waves along the opposite directions when the film thickness is small. In this work, we experimentally realize unidirectional microwave transduction with sub-micrometer-wavelength propagating magnons in a yttrium iron garnet (YIG) thin-film delay line. We achieve a non-decaying isolation of 30 dB with a broad field-tunable bandpass frequency range up to 14 GHz. The large isolation is due to the selection of chiral magnetostatic surface spin waves with the Oersted field generated from the coplanar waveguide antenna. Increasing the geometry ratio between the antenna width and YIG thickness drastically reduces the nonreciprocity and introduces additional magnon transmission bands. Our results pave the way for on-chip microwave isolation and tunable delay line with short-wavelength magnonic excitations.

Simultaneous Detection of Two Extracellular Vesicle Subpopulations in Saliva Assisting Tumor T Staging of Oral Squamous Cell Carcinoma.

Extracellular vesicles (EVs), acting as important mediators of intercellular communication, play an essential role in physiological processes, which have unique potential in the medical field. However, the heterogeneity of EVs limits their development for disease diagnosis and therapy, making the EV subpopulation analysis extremely valuable. In this article, a simple microfluidic approach was presented for the on-chip specific isolation and detection of two phenotypes of EVs (Annexin V+ EGFR+ EVs and Annexin V- EGFR+ EVs) based on different biomolecule-modified magnetic nanospheres and a fluorescence labeling technique. Combined with the control of the magnetic field in the microzone and fluid flow, it was easy to form two separate functional regions in the chip to capture different EV subpopulations. This method was successfully applied to the tests of clinical saliva samples in 75 oral squamous cell carcinoma (OSCC) patients and 10 healthy people. The results showed that the total level of EGFR+ EVs was much higher in OSCC patients that in healthy people. Meantime, the ratio of Annexin V+ EGFR+ EVs to Annexin V- EGFR+ EVs was found to be negatively correlated with tumor T stage of OSCC patients with a statistical difference, which suggested the ratio as a clinical index for monitoring the progression of OSCC in real time based on a noninvasive method. The approach provided a novel idea for evaluating the tumor T stage of OSCC and a powerful tool for clinical application.

Nonreciprocal sideband responses in a spinning microwave magnomechanical system.

Nonreciprocal sideband responses in a spinning microwave magnomechanical system consists of a spinning resonator coupled with a yttrium iron garnet sphere are proposed. We show that the efficiency of sideband generation can be enhanced in one driving direction but restrained in the opposite. This nonreciprocity results from Sagnac effect induced by the spinning resonator, leading to asymmetric magnonic responses in two different driving directions. Beyond the conventional linearized description, the properties of nonreciprocal two-color second-order sideband are demonstrated. By adjusting Sagnac-Fizeau shift and the power of control field, the degree of asymmetric magnonic responses can be strengthened, therefore causing stronger nonreciprocity of sideband. Especially, for the case of strong Sagnac-Fizeau shift and the control field, high level of efficiency and isolation ratio of sideband are achieved simultaneously and the operational bandwidth of strong nonreciprocity can be expanded. Our proposal provides an effective avenue for the manipulation of the nonreciprocity of sideband and has potentially practical applications in on-chip microwave isolation devices and magnon-based precision measurement.

Integrated passive nonlinear optical isolators

Fibre and bulk optical isolators are widely used to stabilize laser cavities by preventing unwanted feedback. However, their integrated counterparts have been slow to be adopted. Although several strategies for on-chip optical isolation have been realized, these rely on either integration of magneto-optic materials or high-frequency modulation with acousto-optic or electro-optic modulators. Here we demonstrate an integrated approach for passively isolating a continuous-wave laser using the intrinsically non-reciprocal Kerr nonlinearity in ring resonators. Using silicon nitride as a model platform, we achieve single ring isolation of 17–23 dB with 1.8–5.5-dB insertion loss, and a cascaded ring isolation of 35 dB with 5-dB insertion loss. Employing these devices, we demonstrate hybrid integration and isolation with a semiconductor laser chip. The intrinsic Kerr nonlinearity in ring resonators is exploited to demonstrate passive isolation of a continuous-wave laser. Up to 35-dB isolation with 5-dB insertion loss was achieved on-chip.

Multi-frequency complete optical isolation based on indirect interband transition

Indirect interband photonic transition is an important approach to achieve on-chip complete optical signal isolation. We demonstrate that the operational isolation bandwidth based on this effect can be increased by utilizing non-interfering transition channels obtained from the process of transition channel engineering. Multiple optical modes can be excited through non-interfering channels and be absorbed by matched filters without interfering with each other, thus achieving multi-frequency complete optical isolation. With two non-interfering transition channels, an optical isolator design that achieves complete isolation at two frequencies is proposed as an example. The potential design of multi-frequency isolator is also discussed. All the results are verified with finite-difference time-domain simulation.

Generation of 3D Spheroids Using a Thiol-Acrylate Hydrogel Scaffold to Study Endocrine Response in ER+ Breast Cancer.

Culturing cancer cells in a three-dimensional (3D) environment better recapitulates in vivo conditions by mimicking cell-to-cell interactions and mass transfer limitations of metabolites, oxygen, and drugs. Recent drug studies have suggested that a high rate of preclinical and clinical failures results from mass transfer limitations associated with drug entry into solid tumors that 2D model systems cannot predict. Droplet microfluidic devices offer a promising alternative to grow 3D spheroids from a small number of cells to reduce intratumor heterogeneity, which is lacking in other approaches. Spheroids were generated by encapsulating cells in novel thiol–acrylate (TA) hydrogel scaffold droplets followed by on-chip isolation of single droplets in a 990- or 450-member trapping array. The TA hydrogel rapidly (∼35 min) polymerized on-chip to provide an initial scaffold to support spheroid development followed by a time-dependent degradation. Two trapping arrays were fabricated with 150 or 300 μm diameter traps to investigate the effect of droplet size and cell seeding density on spheroid formation and growth. Both trapping arrays were capable of ∼99% droplet trapping efficiency with ∼90% and 55% cellular encapsulation in trapping arrays containing 300 and 150 μm traps, respectively. The oil phase was replaced with media ∼1 h after droplet trapping to initiate long-term spheroid culturing. The growth and viability of MCF-7 3D spheroids were confirmed for 7 days under continuous media flow using a customized gravity-driven system to eliminate the need for syringe pumps. It was found that a minimum of 10 or more encapsulated cells are needed to generate a growing spheroid while fewer than 10 parent cells produced stagnant 3D spheroids. As a proof of concept, a drug susceptibility study was performed treating the spheroids with fulvestrant followed by interrogating the spheroids for proliferation in the presence of estrogen. Following fulvestrant exposure, the spheroids showed significantly less proliferation in the presence of estrogen, confirming drug efficacy.

A micropillar array-based microfluidic chip for label-free separation of circulating tumor cells: The best micropillar geometry?

IntroductionThe information derived from the number and characteristics of circulating tumor cells (CTCs), is crucial to ensure appropriate cancer treatment monitoring. Currently, diverse microfluidic platforms have been developed for isolating CTCs from blood, but it remains a challenge to develop a low-cost, practical, and efficient strategy. ObjectivesThis study aimed to isolate CTCs from the blood of cancer patients via introducing a new and efficient micropillar array-based microfluidic chip (MPA-Chip), as well as providing prognostic information and monitoring the treatment efficacy in cancer patients. MethodsWe fabricated a microfluidic chip (MPA-Chip) containing arrays of micropillars with different geometries (lozenge, rectangle, circle, and triangle). We conducted numerical simulations to compare velocity and pressure profiles inside the micropillar arrays. Also, we experimentally evaluated the capture efficiency and purity of the geometries using breast and prostate cancer cell lines as well as a blood sample. Moreover, the device’s performance was validated on 12 patients with breast cancer (BC) in different states. ResultsThe lozenge geometry was selected as the most effective and optimized micropillar design for CTCs isolation, providing high capture efficiency (>85 %), purity (>90 %), and viability (97 %). Furthermore, the lozenge MPA-chip was successfully validated by the detection of CTCs from 12 breast cancer (BC) patients, with non-metastatic (median number of 6 CTCs) and metastatic (median number of 25 CTCs) diseases, showing different prognoses. Also, increasing the chemotherapy period resulted in a decrease in the number of captured CTCs from 23 to 7 for the metastatic patient. The MPA-Chip size was only 0.25 cm2 and the throughput of a single chip was 0.5 ml/h, which can be increased by multiple MPA-Chips in parallel. ConclusionThe lozenge MPA-Chip presented a novel micropillar geometry for on-chip CTC isolation, detection, and staining, and in the future, the possibilities can be extended to the culture of the CTCs.

A Novel 61.25 GHz Monostatic CMOS Interrogator for Batteryless Backscattering RFID Solutions

This article presents the analysis, design, and characterization of a 61.25 GHz radio frequency identification (RFID) interrogator. Monostatic RFID systems have to solve the challenge of the transmit (TX)-to-receive (RX) leakage, which could desensitize the interrogator. Instead of suppressing or canceling this leakage, the interference of the transmitted and incident waves is exploited to demodulate the incident signal. The structure can be inserted between the power amplifier (PA) and the antenna pad of existing transmitters. It has a lower insertion loss (IL) than other ON-chip isolation structures used in monostatic interrogators reported to date. The transceiver front-end was fabricated on a 22 nm fully depleted silicon on insulator (FD-SOI) technology, and has a simple structure, where the low-power receiver requires 0.022 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> active area. The die was mounted on a radio frequency (RF) printed circuit board (PCB) and a general circuit board was used for baseband processing in the measurements.

Requirement Analysis and Teardrop-Based Design of High Antenna Isolation for FMCW Radar

Frequency-modulated continuous wave (FMCW) radar is widely used in automotive and consumer electronics because of its range, velocity, and angle measurement functionality. In an FMCW radar system, the isolation between transmitting (Tx) and receiving (Rx) subsystems affects the sensitivity of the FMCW system, which directly impacts the system’s overall performance in target detection. The factors that affect system performance include transmitter-to-receiver on-chip coupling and Tx-to-Rx antenna coupling. The on-chip isolation performance is basically fixed once a radar chip is given, but the antenna isolation performance depends on a designed antenna array. Usually, a targeted antenna requirement is first specified, and then the corresponding Tx and Rx antenna array is designed. However, there is no general principle or criteria for specifying a proper antenna isolation requirement in the existing research. In this paper, first, we reveal that the antenna isolation requirement should be set to be almost the same as the given on-chip isolation value, which is very significant as a general guideline in setting a targeted antenna isolation requirement. All current antenna isolation methods cannot reach the level of on-chip isolation in a compactly designed radar system. We further propose a teardrop-based method to provide high antenna isolation. The principle of an antenna isolation requirement and a novel antenna design using teardrops are both analyzed and demonstrated based on a representative 24 GHz FMCW radar. Our teardrop-shaped structure in the mouth of the conventional Vivaldi antenna achieved greater than 50 dB isolation, while the distance between the Tx and Rx antennas could be reduced to 2.1 mm.

Rapid On-Chip Isolation of Cancer-Associated Exosomes and Combined Analysis of Exosomes and Exosomal Proteins.

Exosomes are lipid bilayer extracellular vesicles secreted by various types of cells and inherit abundant molecular information from parental cells. Tumor-derived exosomes have been widely recognized as noninvasive biomarkers for early cancer diagnosis and surveillance, but the separation of intact exosomes and detection of exosomal proteins remain challenging. Herein, we proposed a microfluidic chip for specific exosome isolation, integrated with sensitive quantification by a novel PTCDI-aptamer signal switch strategy. To enhance the capture efficiency, an alternating drop-shaped micropillar array was designed to assist the capture of tumor-derived exosomes by Tim4-modified magnetic beads (Tim4 beads) on the chip. Following capture, a chelating agent can easily elute intact exosomes which were further used for profiling exosomal surface proteins by the multiplexed fluorescence turn-on approach. Profiting from the efficient on-chip enrichment of the Tim4 beads and superior fluorescence signal transduction strategy, the detection limit of the analysis platform for HepG2 exosomes is as low as 8.69 × 103 particles/mL with a wide linear range spanning 6 orders of magnitude. Meanwhile, the proposed platform could recognize subtle changes in protein levels on the exosomal surface from various cell lines. More importantly, this strategy is successfully applied to analyze exosomes in human serum to distinguish liver cancer patients from healthy individuals. Combined analysis of different types of biomarkers on the exosomal membrane surface can greatly improve the accuracy of cancer type identification and disease monitoring. We hope that this convenient, rapid, and sensitive platform may become a powerful tool in the field of exosome analysis and early cancer screening.

A Novel Conformal Thick Oxide Technology for On-Chip High-Voltage Isolation

In this letter, a novel conformal thick oxide technology is proposed and demonstrated for on-chip high-voltage isolation. The proposed technology utilizes alternate deposition and oxidation of polysilicon to form thick high-quality conformal oxide with a reasonable process time. Experimental results show that breakdown voltages (BVs) as high as 4.19 kV can be achieved with double-side, 6-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula>-thick planar oxide layers formed using this technology. Excellent conformity was also observed inside deep silicon trenches. The double-side, silicon-embedded transformer (DSSET) fabricated using this isolation layer technology achieved an isolation capability of 1.84 kV.

"Cells-to-cDNA on Chip": Phenotypic Assessment and Gene Expression Analysis from Live Cells in Nanoliter Volumes Using Droplet Microarrays.

In vitro cell-based experiments are particularly important in fundamental biological research. Microscopy-based readouts to identify cellular changes in response to various stimuli are a popular choice, but gene expression analysis is essential to delineate the underlying molecular dynamics in cells. However, cell-based experiments often suffer from interexperimental variation, especially while using different readout methods. Therefore, establishment of platforms that allow for cell screening, along with parallel investigations of morphological features, as well as gene expression levels, is crucial. The droplet microarray (DMA) platform enables cell screening in hundreds of nanoliter droplets. In this study, a "Cells-to-cDNA on Chip" method is developed enabling on-chip mRNA isolation from live cells and conversion to cDNA in individual droplets of 200 nL. This novel method works efficiently to obtain cDNA from different cell numbers, down to single cell per droplet. This is the first established miniaturized on-chip strategy that enables the entire course of cell screening, phenotypic microscopy-based assessments along with mRNA isolation and its conversion to cDNA for gene expression analysis by real-time PCR on an open DMA platform. The principle demonstrated in this study sets a beginning for myriad of possible applications to obtain detailed information about the molecular dynamics in cultured cells.

Small magnetless integrated optical isolator using a magnetized cobalt ferrite film

We experimentally demonstrated a silicon optical isolator using a monolithically integrated cobalt ferrite (CFO) film as magneto-optical material, achieving an isolation ratio of 9.6dB near 1550nm wavelength. By virtue of the large Faraday rotation coefficient of CFO, the device has a compact footprint comparing to the current yttrium iron garnet-based isolators. Furthermore, we demonstrated self-biased isolation by the strong remanence of CFO films, eliminating the tedious demand of an external magnet. Cobalt ferrite represents a potential alternative approach to yttrium iron garnets to realize a practical device for on-chip isolation in silicon photonic integrated circuits because of the small footprint.

Multiple exosome RNA analysis methods for lung cancer diagnosis through integrated on-chip microfluidic system

Exosomes are now raising focus as a prospective biomarker for cancer diagnostics and prognosis owing to its unique bio-origin and composition. Exosomes take part in cellular communication and receptor mediation and transfer their cargos (e.g., proteins, mRNA and DNA). Quantitative analysis of tumor-related nucleic acid mutations can be a potential method to cancer diagnosis and prognosis in early stages. Here we present an integrated microfluidic system for exosome on-chip isolation and lung cancer RNA analysis through droplet digital PCR (ddPCR). Gradient dilution experiments show great linearity over a large concentration range with R2 = 0.9998. Utilizing the system, four cell lines and two mutation targets were parallelly detected for mutation analysis. The experiments demonstrated mutation heterogeneity and the results were agree with cell researches. These results proved our integrated microfluidic system as a promising means for early cancer diagnosis and prognosis in the era of liquid biopsy.

Advances in Biosensors Technology for Detection and Characterization of Extracellular Vesicles.

Exosomes are extracellular vehicles (EVs) that encapsulate genomic and proteomic material from the cell of origin that can be used as biomarkers for non-invasive disease diagnostics in point of care settings. The efficient and accurate detection, quantification, and molecular profiling of exosomes are crucial for the accurate identification of disease biomarkers. Conventional isolation methods, while well-established, provide the co-purification of proteins and other types of EVs. Exosome purification, characterization, and OMICS analysis are performed separately, which increases the complexity, duration, and cost of the process. Due to these constraints, the point-of-care and personalized analysis of exosomes are limited in clinical settings. Lab-on-a-chip biosensing has enabled the integration of isolation and characterization processes in a single platform. The presented review discusses recent advancements in biosensing technology for the separation and detection of exosomes. Fluorescent, colorimetric, electrochemical, magnetic, and surface plasmon resonance technologies have been developed for the quantification of exosomes in biological fluids. Size-exclusion filtration, immunoaffinity, electroactive, and acoustic-fluid-based technologies were successfully applied for the on-chip isolation of exosomes. The advancement of biosensing technology for the detection of exosomes provides better sensitivity and a reduced signal-to-noise ratio. The key challenge for the integration of clinical settings remains the lack of capabilities for on-chip genomic and proteomic analysis.