Preservation of Proteins in Human Plasma through Metal-Organic Framework Encapsulation.

Traditional cold chain systems of collection, transportation, and storage of biofluid specimens for eventual analysis pose a huge financial and environmental burden. These systems are impractical in pre-hospital and resource-limited settings, where refrigeration and electricity are not reliable or even available. Here, we develop an innovative technology using metal-organic frameworks (MOFs), a novel class of organic-inorganic hybrids with high thermal stability, as encapsulates for preserving the integrity of protein biomarkers in biofluids under ambient or non-refrigerated storage conditions.

Biochemical network analysis of protein-protein interactions to follow-up T1 bladder cancer patients.

Bladder cancer (BCa) is a prevalent disease with a high risk of aggressive recurrence in T1-stage patients. Despite the efforts to anticipate recurrence, a reliable method has yet to be developed. In this work, we employed high-resolution mass spectrometry to compare the urinary proteome of T1-stage BCa patients with recurring versus non-recurring disease to uncover actionable clinical information predicting recurrence.

Ultrasensitive lateral-flow assays via plasmonically active antibody-conjugated fluorescent nanoparticles.

Lateral-flow assays (LFAs) are rapid and inexpensive, yet they are nearly 1,000-fold less sensitive than laboratory-based tests. Here we show that plasmonically active antibody-conjugated fluorescent gold nanorods can make conventional LFAs ultrasensitive. With sample-to-answer times within 20 min, plasmonically enhanced LFAs read out via a standard benchtop fluorescence scanner attained about 30-fold improvements in dynamic range and in detection limits over 4-h-long gold-standard enzyme-linked immunosorbent assays, and achieved 95% clinical sensitivity and 100% specificity for antibodies in plasma and for antigens in nasopharyngeal swabs from individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

High-resolution imaging of protein secretion at the single-cell level using plasmon-enhanced FluoroDOT assay.

Secreted proteins mediate essential physiological processes. With conventional assays, it is challenging to map the spatial distribution of proteins secreted by single cells, to study cell-to-cell heterogeneity in secretion, or to detect proteins of low abundance or incipient secretion. Here, we introduce the "FluoroDOT assay," which uses an ultrabright nanoparticle plasmonic-fluor that enables high-resolution imaging of protein secretion.

Plasmon-enhanced Quantitative Lateral Flow Assay for Femtomolar Detection of SARS-CoV-2 Antibodies and Antigens.

Lateral flow assays (LFAs) are the cornerstone of point-of-care diagnostics. Although rapid and inexpensive, they are 1000-fold less sensitive than laboratory-based tests and cannot be used for definitive negative diagnosis. Here, we overcome this fundamental limitation by employing plasmonically-enhanced nanoscale colorimetric and fluorescent labels.

Plasmonically-enhanced competitive assay for ultrasensitive and multiplexed detection of small molecules.

Novel methods that enable facile, ultrasensitive and multiplexed detection of low molecular weight organic compounds such as metabolites, drugs, additives, and organic pollutants are valuable in biomedical research, clinical diagnosis, food safety and environmental monitoring. Here, we demonstrate a simple, rapid, and ultrasensitive method for detection and quantification of small molecules by implementing a competitive immunoassay with an ultrabright fluorescent nanolabel, plasmonic fluor. Plasmonic-fluor is comprised of a polymer-coated gold nanorod and bovine serum albumin conjugated with molecular fluorophores and biotin.

Plasmonically Enhanced Ultrasensitive Epitope-Specific Serologic Assay for COVID-19.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has rapidly spread and resulted in the global pandemic of COVID-19. Although IgM/IgG serology assay has been widely used, with the entire spike or nucleocapsid antigens, they only indicate the presence or absence of antibodies against these proteins but are not specific to the neutralization antibodies, therefore providing only generic information about infection stage and possible future immune protection. Novel technologies enabling easy-to-use and sensitive detection of multiple specific antibodies simultaneously will facilitate precise diagnosis of infection stage, prediction of clinical outcomes, and evaluation of future immune protection upon viral exposure or vaccination.

Plasmonically Enhanced CRISPR/Cas13a-Based Bioassay for Amplification-Free Detection of Cancer-Associated RNA.

Novel methods that enable sensitive, accurate and rapid detection of RNA would not only benefit fundamental biological studies but also serve as diagnostic tools for various pathological conditions, including bacterial and viral infections and cancer. Although highly sensitive, existing methods for RNA detection involve long turn-around time and extensive capital equipment. Here, an ultrasensitive and amplification-free RNA quantification method is demonstrated by integrating CRISPR-Cas13a system with an ultrabright fluorescent nanolabel, plasmonic fluor.

Enhancing the Stability of COVID-19 Serological Assay through Metal-Organic Framework Encapsulation.

Enzyme-linked immunosorbent assay is widely utilized in serologic assays, including COVID-19, for the detection and quantification of antibodies against SARS-CoV-2. However, due to the limited stability of the diagnostic reagents (e.g.

Ultrabright plasmonic fluor nanolabel-enabled detection of a urinary ER stress biomarker in autosomal dominant tubulointerstitial kidney disease.

Autosomal dominant tubulointerstitial kidney disease (ADTKD)-uromodulin ( is the most common nonpolycystic genetic kidney disease, but it remains unrecognized due to its clinical heterogeneity and lack of screening test. Moreover, the fact that the clinical feature is a poor predictor of disease outcome further highlights the need for the development of mechanistic biomarkers in ADTKD. However, low abundant urinary proteins secreted by thick ascending limb cells, where UMOD is synthesized, have posed a challenge for the detection of biomarkers in ADTKD-.

Gold Nanorod Size-Dependent Fluorescence Enhancement for Ultrasensitive Fluoroimmunoassays.

Plasmon-enhanced fluorescence (PEF) is a simple and highly effective approach for improving the signal-to-noise ratio and sensitivity of various fluorescence-based bioanalytical techniques. Here, we show that the fluorescence enhancement efficacy of gold nanorods (AuNRs), which are widely employed for PEF, is highly dependent on their absolute dimensions (i.e.

Microneedle patch for the ultrasensitive quantification of protein biomarkers in interstitial fluid.

The detection and quantification of protein biomarkers in interstitial fluid is hampered by challenges in its sampling and analysis. Here we report the use of a microneedle patch for fast in vivo sampling and on-needle quantification of target protein biomarkers in interstitial fluid. We used plasmonic fluor-an ultrabright fluorescent label-to improve the limit of detection of various interstitial fluid protein biomarkers by nearly 800-fold compared with conventional fluorophores, and a magnetic backing layer to implement conventional immunoassay procedures on the patch and thus improve measurement consistency.

Polydopamine-Mesoporous Silica Core-Shell Nanoparticles for Combined Photothermal Immunotherapy.

Cancer immunotherapy involves a cascade of events that ultimately leads to cytotoxic immune cells effectively identifying and destroying cancer cells. Responsive nanomaterials, which enable spatiotemporal orchestration of various immunological events for mounting a highly potent and long-lasting antitumor immune response, are an attractive platform to overcome challenges associated with existing cancer immunotherapies. Here, we report a multifunctional near-infrared (NIR)-responsive core-shell nanoparticle, which enables (i) photothermal ablation of cancer cells for generating tumor-associated antigen (TAA) and (ii) triggered release of an immunomodulatory drug (gardiquimod) for starting a series of immunological events.

Ultrabright fluorescent nanoscale labels for the femtomolar detection of analytes with standard bioassays.

The detection and quantification of low-abundance molecular biomarkers in biological samples is challenging. Here, we show that a plasmonic nanoscale construct serving as an 'add-on' label for a broad range of bioassays improves their signal-to-noise ratio and dynamic range without altering their workflow and readout devices. The plasmonic construct consists of a bovine serum albumin scaffold with approximately 210 IRDye 800CW fluorophores (with a fluorescence intensity approximately 6,700-fold that of a single 800CW fluorophore), a polymer-coated gold nanorod acting as a plasmonic antenna and biotin as a high-affinity biorecognition element.

Refreshable Nanobiosensor Based on Organosilica Encapsulation of Biorecognition Elements.

Implantable and wearable biosensors that enable monitoring of biophysical and biochemical parameters over long durations are highly attractive for early and presymptomatic diagnosis of pathological conditions and timely clinical intervention. Poor stability of antibodies used as biorecognition elements and the lack of effective methods to refresh the biosensors upon demand without severely compromising the functionality of the biosensor remain significant challenges in realizing protein biosensors for long-term monitoring. Here, we introduce a novel method involving organosilica encapsulation of antibodies for preserving their biorecognition capability under harsh conditions, typically encountered during the sensor refreshing process, and elevated temperature.

Bioplasmonic paper-based assay for perilipin-2 non-invasively detects renal cancer.

Renal cell carcinoma (RCC) has poor survival prognosis because it is asymptomatic at an early, more curative stage. Recently, urine perilipin-2 (PLIN-2) was demonstrated to be a sensitive and specific biomarker for the noninvasive, early detection of RCC and an indispensable indicator to distinguish cancer from a benign renal mass. However, current Western blot or ELISA PLIN-2 assays are complicated, expensive, time-consuming or insensitive, making them unsuitable for routine analysis in clinical settings.

Add-on plasmonic patch as a universal fluorescence enhancer.

Fluorescence-based techniques are the cornerstone of modern biomedical optics, with applications ranging from bioimaging at various scales (organelle to organism) to detection and quantification of a wide variety of biological species of interest. However, the weakness of the fluorescence signal remains a persistent challenge in meeting the ever-increasing demand to image, detect, and quantify biological species with low abundance. Here, we report a simple and universal method based on a flexible and conformal elastomeric film with adsorbed plasmonic nanostructures, which we term a "plasmonic patch," that provides large (up to 100-fold) and uniform fluorescence enhancement on a variety of surfaces through simple transfer of the plasmonic patch to the surface.

Urinary aquaporin 1 and perilipin 2: Can these novel markers accurately characterize small renal masses and help guide patient management?

Objective: To evaluate the role of urine aquaporin 1 and perilipin 2 as biomarkers adjunct to renal mass biopsy in guiding the management of patients with small renal masses.

Methods: Preoperative aquaporin 1 and perilipin 2 levels in 57 patients with small renal masses undergoing partial nephrectomy were analyzed and compared with postoperative tumor histology. An algorithm was created utilizing aquaporin 1 and perilipin 2 in conjunction with renal mass biopsy.

Metal-Organic Framework Encapsulation Preserves the Bioactivity of Protein Therapeutics.

Protein therapeutics are prone to lose their structure and bioactivity under various environmental stressors. This study reports a facile approach using a nanoporous material, zeolitic imidazolate framework-8 (ZIF-8), as an encapsulant for preserving the prototypic protein therapeutic, insulin, against different harsh conditions that may be encountered during storage, formulation, and transport, including elevated temperatures, mechanical agitation, and organic solvent. Both immunoassay and spectroscopy analyses demonstrate the preserved chemical stability and structural integrity of insulin offered by the ZIF-8 encapsulation.

Environmental Stability of Plasmonic Biosensors Based on Natural versus Artificial Antibody.

Plasmonic biosensors based on the refractive index sensitivity of localized surface plasmon resonance (LSPR) are considered to be highly promising for on-chip and point-of-care biodiagnostics. However, most of the current plasmonic biosensors employ natural antibodies as biorecognition elements, which can easily lose their biorecognition ability upon exposure to environmental stressors (e.g.

Ultrarobust Biochips with Metal-Organic Framework Coating for Point-of-Care Diagnosis.

Most biosensors relying on antibodies as recognition elements fail in harsh environment conditions such as elevated temperatures, organic solvents, or proteases because of antibody denaturation, and require strict storage conditions with defined shelf life, thus limiting their applications in point-of-care and resource-limited settings. Here, a metal-organic framework (MOF) encapsulation is utilized to preserve the biofunctionality of antibodies conjugated to nanotransducers. This study investigates several parameters of MOF coating (including growth time, surface morphology, thickness, and precursor concentrations) that determine the preservation efficacy against different protein denaturing conditions in both dry and wet environments.

Rapid, Point-of-Care, Paper-Based Plasmonic Biosensor for Zika Virus Diagnosis.

Zika virus (ZIKV) is an increasing global health challenge. There is an urgent need for rapid, low-cost, and accurate diagnostic tests that can be broadly distributed and applied in pandemic regions. Here, an innovative, adaptable, and rapidly deployable bioplasmonic paper-based device (BPD) is demonstrated for the detection of ZIKV infection, via quantification of serum anti-ZIKV-nonstructural protein 1 (NS1) IgG and IgM.

Single Molecule Force Spectroscopy to Compare Natural versus Artificial Antibody-Antigen Interaction.

Biorecognition is central to various biological processes and finds numerous applications in virtually all areas of chemistry, biology, and medicine. Artificial antibodies, produced by imprinting synthetic polymers, are designed to mimic the biological recognition capability of natural antibodies, while exhibiting superior thermal, chemical, and environmental stability compared to their natural counterparts. The binding affinity of the artificial antibodies to their antigens characterizes the biorecognition ability of these synthetic nanoconstructs and their ability to replace natural recognition elements.

Aromatic Functionality of Target Proteins Influences Monomer Selection for Creating Artificial Antibodies on Plasmonic Biosensors.

Natural antibodies used as biorecognition elements suffer from numerous shortcomings, such as limited chemical and environmental stability and cost. Artificial antibodies based on molecular imprinting are an attractive alternative to natural antibodies. We investigated the role of aromatic interactions in target recognition capabilities of artificial antibodies.

Metal-Organic Framework as a Protective Coating for Biodiagnostic Chips.

Zeolitic imidazolate framework-8 (ZIF-8) grown around antibodies anchored to plasmonic nanostructures serves as a protective layer to preserve the biorecognition ability of antibodies stored at room and elevated temperatures for several days. The biofunctionality of the ZIF-8-protected biochip can be restored by a simple water-rinsing step, making it highly convenient for use in point-of-care and resource-limited settings.