Novel Near-infrared Research Articles

Development and Preclinical Evaluation of a Near-Infrared Fluorescence Probe Based on Tailored Hepatitis B Core Particles for Imaging-Guided Surgery in Breast Cancer.

PurposeTumor-free surgical margin is crucial but challenging in breast-conserving surgery (BCS). Fluorescence imaging is a promising strategy for surgical navigation that can reliably assist the surgeon with visualization Of the tumor in real-time. Notably, finding an optimized fluorescent probe has been a challenging research topic. Herein, we developed a novel near-infrared (NIR) fluorescent probe based on tailored Hepatitis B Core virus-like protein (HBc VLP) and presented the preclinical imaging-guided surgery.MethodsThe RGD-HBc160 VLP was synthesized by genetic engineering followed encapsulation of ICG via disassembly-reassembly. The applicability of the probe was tested for cell and tissue binding capacities through cell-based plate assays, xenograft mice model, and MMTV-PyVT mammary tumor transgenic mice. Subsequently, the efficacy of RGD-HBc160/ICG-guided surgery was evaluated in an infiltrative tumor-bearing mouse model. The protein-induced body’s immune response was further assessed.ResultsThe prepared RGD-HBc160/ICG showed outstanding integrin αvβ3 targeting ability in vitro and in vivo. After intravenous administration of probe, the fluorescence guidance facilitated more complete tumor resection and improved overall survival Of the infiltrative tumor-bearing mice. The probe also showed the excellent capability to differentiate between benign and malignant breast tissues in the mammary tumor transgenic mice. Interestingly, the ingenious tailoring of HBc VLP could not only endow its tumor-targeting ability towards integrin αvβ3 but also significantly reduce the humoral and cellular immune response.ConclusionThe RGD-HBc160/ICG holds promise as an effective tool to delineate tumor margin. These results have translational potential to achieve margin-negative resection and improve the stratification of patients for a potentially curative.

Ratiometric detection and bioimaging of endogenous alkaline phosphatase by a NIR fluorescence probe

A novel near-infrared (NIR) fluorescent probe (SWJT-3) was designed based on phosphate protection of the electron donating group of the hemicyanine for the ratiometric determination of ALP at 590 and 670 nm. Notably, SWJT-3 could be used in the endogenous detection of ALP in vitro and vivo. Moreover, it was the first NIR and ratiometric fluorescent probe for the imaging of ALP in mice. It has large Stokes shift (185 nm), and also showed high selectivity, low detection limit (0.87 U/L). Meanwhile, SWJT-3 exhibited obvious color change in aqueous solution which could be observed by naked-eyes. In addition, the probe displayed low lifetime (0.74 ns), high substrate affinity (Km = 8.89 µM) and excellent fluorescence characterization under various polarity and viscosity conditions.

Near-infrared fluorescent probe for sensing local microscopic extreme acidity and its application in mitochondria

In this paper, a novel near-infrared (NIR) fluorescent probe Cy-BNN for sensing local microscopic pH under extremely acidic conditions (pH < 4) was constructed and reported. For the preparation of Cy-BNN, a barbituric acid moiety was fused in the polymethine chain of the cyanine dye to introduce nitrogen atoms as protonation center. In different pH, the balance of quaternary ammonium salts and free amines of Cy-BNN was adjusted, and the pka value of Cy-BNN was calculated based on the Sigmoidal equation. Surprisingly, the pka value of Cy-BNN as low as 3.32, implying that Cy-BNN can be used for sensing extreme acidity. As expected, Cy-BNN exhibited highly selective response to H+ over diverse analytes, and can be used to monitoring the intracellular pH fluctuation under extremely acidic conditions. Importantly, Cy-BNN can be used to specifically target mitochondria, providing potential possibilities for monitoring mitochondria–lysosome interactions in live cells and mitophagy process.

Highly Sensitive, Non-cryogenic NIR High-resolution Spectrograph, WINERED

WINERED is a novel near-infrared (NIR) high-resolution spectrograph (HRS) that pursues the highest possible sensitivity to realize high-precision spectroscopy in the NIR as in the optical wavelength range. WINERED covers 0.9–1.35 μm (z, Y, and J-bands) with three modes (Wide mode and two Hires modes) at the maximum spectral resolutions of R = 28,000 and R = 70,000. For fulfilling the objective, WINERED is designed with an unprecedentedly high instrument throughput (up to 50% at maximum including the quantum efficiency of the array) that is three times or more than other existing optical/NIR HRSs. This is mainly realized by a combination of non-white pupil and no fiber-fed configuration in optical design, the moderate (optimized) wavelength coverage, and the high-throughput gratings. Another prominent feature of WINERED is “warm” instrument despite for infrared (IR) observations. Such non-cryogenic (no cold stop) IR instrument finally became possible with the combination of custom-made thermal-cut filter of 10−8 class, 1.7 μm cutoff HAWAII-2RG array, and a cold baffle reducing the direct thermal radiation to the IR array into the solid angle of f/2. The thermal background is suppressed below 0.1 photons pixel−1 s−1 even in the wide band of 0.9–1.35 μm under the environment of 290 K. WINERED had been installed to the 3.58 m New Technology Telescope at La Silla Observatory, ESO, since 2017. Even with the intermediate size telescope, WINERED was confirmed to provide a limiting magnitude (for SNR = 30 with 8 hr. integration time) of J = 16.4 mag for the Wide mode and J = 15.1 mag for the Hires mode, respectively, under the natural seeing conditions. These sensitivities are comparable to those for the existing NIR-HRSs attached to the 8–10 m class telescopes with AO. WINERED type spectrographs may become a critical not only for the currently on-going extremely large telescopes to reduce the developing cost and time but also for smaller telescopes to extend their lives with long programs.

A novel afterglow nanoreporter for monitoring cancer therapy.

Rationale: Immunogenic cell death (ICD)-associated immunogenicity evoked through reactive oxygen species (ROS) is an efficient way to fight against the immune-dysfunctional microenvironment, so as to provoke potent anti-tumor immunity. However, the unknown ROS dose during cancer therapies may induce adverse immune responses (e.g., insufficient ICD, toxicity toward normal tissues or immune system).Methods: Herein, we developed a pyrido pyrazine - thiophene based semiconducting polymer as novel near-infrared (NIR) organic afterglow nanoparticles for the real-time visualization of self-generated ROS, during photodynamic-mediated immunogenic cell death. Specifically, we introduced the strong “acceptor” (pyrido pyrazine) into thiophene based semiconducting polymer to redshift emission wavelength, and further modulate the “donor” to afford more afterglow reaction sites and reducing ΔEst, so as to enhance luminescence intensity.Results: The semiconducting polymer-based afterglow nanoparticles exhibit strong afterglow emission with longer-wavelength emission (> 800 nm), compared with the reported organic afterglow nanoparticles (e.g., MEHPPV, PFODBT or Chlorin, < 690 nm), which endows this afterglow nanoparticles with a greatly improvement of signal to noise ratio. Moreover, the photodynamic effect of this afterglow nanoparticles can induce immunogenic cell death of cancer cells and further cause immune responses in mice.Conclusions: The NIR afterglow signal presents a good relationship with ROS generation, immunogenic cell death and outcome of treatment. Therefore, it was able to provide a non-invasive tool for predicting the degree of ICD that occurs during ROS-mediated cancer therapy and may contribute to precise immunotherapy.

Intense infrared emission of Er3+ in ZnB2O4 phosphors from energy transfer of Bi3+ by broadband UV excitation

A novel near-infrared (NIR) emitting ZnB2O4:Bi3+, Er3+ phosphor has been synthesized using a conventional solid-state reaction method. The X-ray diffraction, Photoluminescence (PL) properties, and PL decay curves of the samples were investigated thoroughly to have an insight into its luminescence performance. The XRD analysis reveals that an increase in annealing time results in the formation of single-phase for the as-prepared ZnB2O4 phosphor. The ZnB2O4:Bi3+, Er3+ phosphor show broadband Bi3+ emission at 428 nm along with an intense characteristic Er3+ NIR emission at 1535 nm under 335 nm excitation. The energy transfer (ET) from Bi3+ to Er3+ ions has also been discussed in detail. The detailed investigations carried out in the present work demonstrate that the incorporation of Bi3+ enhances the NIR emission intensity of Er3+ at 1535 nm by about 12 times. The critical distances (Rc) between Bi3+ and Er3+ for ET in ZnB2O4 were calculated by concentration quenching and turned out to be around 16.42 Å. The result indicates that the Er3+ NIR emission can be effectively sensitized via Bi3+:1S0→3P1 transition in ZnB2O4 phosphor.

Surface-enhanced Raman scattering labeled nanoplastic models for reliable bio-nano interaction investigations

Nanoplastics (NPs) have attracted great attention as an emerging pollution. To date, their interaction with biological systems has been studied mostly by using fluorescent-labeled NPs, which suffered from serious drawbacks such as biological autofluorescence interference and false-positive results. Reliable optically labeled NP models are eagerly desired until now. Herein, a novel near-infrared (NIR) surface-enhanced Raman scattering (SERS) labeled NP model was proposed, which gained single-particle ultra-sensitivity, deep tissue detection, multiplex labeling ability, and anti-interference property. More importantly, the NP demonstrated satisfactory in vivo signal stability which completely prevented the positive-false problems. The advantages of the NPs enabled direct, dynamic in vivo behavior imaging study in living zebrafish embryo, adult zebrafish and green vegetable Brassica rapa. It was found for the first time that NPs entered blood circulation system of zebrafish larva via dermal uptake route, which only occurred in a short 48 h-window post-hatch. NPs widely distributed in roots, shoots and leaves of Brassica rapa seedlings germinating and growing in the NP-containing hydroponic culture. Different depths of one root showed varied adsorption capabilities towards NPs with fulvic acid, lipid and sodium dodecyl sulfate eco-coronas. This work provided an ideal tool for reliable bio-NP interaction study for a variety of organisms, which could promote the research of NPs.

Determination of alcohols-diesel oil by near infrared spectroscopy based on gramian angular field image coding and deep learning

Alcohols blended with diesel, as a renewable and clean substitute fuel of diesel engine, is a potential solution to alleviate the scarcity of fossil fuels and the worsening environmental pollution in transportation and industry. In this study, a novel near infrared (NIR) application for determination of alcohols-diesel is presented. Using the strategy of combining NIR spectroscopy with gramian angular field (GAF) image coding and deep convolution neural network (CNN), the proposed approach successfully realized the qualitative classification of different diesel (methanol diesel, ethanol diesel and pure diesel) and alcohols content detection despite the spectra were highly similar and collinear. To further verify the practical performance of the proposed method, it was briefly compared with 1DCNN, support vector machine (SVM) and BP neural network based on the identical data. The proposed GAF-CNN method can accurately distinguish diesel, methanol diesel and ethanol diesel. In addition, satisfactory results have been achieved with the smallest MSE and MAE and the highest R2 in the quantitative detection of methanol and ethanol content. This study explores the conversion of 1D spectra into 2D images through the mathematical of GAF, which not only opens up a new perspective for more intuitive display of spectral features, but also makes it possible to introduce the powerful advantages of deep learning image processing into the field of NIR analysis. The proposed method provides a new idea for the intelligent determination of alcohols-diesel.

Real-Time Visualization of Embryonic Apoptosis Using a Near-Infrared Fluorogenic Probe for Embryo Development Evaluation.

Developing an accurate and reliable detection technique for early embryonic apoptosis is of great significance for real-time monitoring and evaluation of embryonic development in living systems. Herein, we have rationally designed and synthesized a novel near-infrared (NIR) fluorogenic probe CGK(QSY21)DEVD-Cy5.5 for real-time imaging of embryonic apoptosis. This probe is constructed with a NIR dye Cy5.5, a fluorescence quencher QSY21, and a peptide substrate Asp-Glu-Val-Asp (DEVD) of the caspase-3 enzyme that is a key executor of cell apoptosis. The probe was initially nonfluorescent in aqueous solution but emitted strong NIR fluorescence upon specific cleavage by activated caspase-3 in a concentration-dependent manner. Taking advantage of this unique feature, this fluorogenic probe was for the first time used for real-time imaging of caspase-3 activity in apoptotic embryos. More notably, significant fluorescence enhancement was solely determined from the apoptotic embryos with the treatment of the probe both in vitro and in vivo, highly suggesting that this probe has great potential to monitor the apoptosis of embryos. We thus envision that this probe would provide a very useful means for real-time visualization and accurate evaluation of embryonic development in the future.

Flav7 + DOX co-loaded separable microneedle for light-triggered chemo-thermal therapy of superficial tumors

Microneedles (MNs) are an attractive strategy for the efficient, painless transdermal delivery of drugs with low systemic toxicity. In this work, a novel near-infrared (NIR) light-triggered separable microneedle system was fabricated to supply controlled chemo-thermal therapy to superficial tumors by co-loading a self-developed NIR-II fluorescence fluorophore Flav7 and the antitumor drug doxorubicin (DOX) in phase-change polycaprolactone (PCL) arrowheads on a soluble base. For the MNs we proposed, Flav7 offers MNs with NIR light-triggered heating generation and drug release properties as well as a NIR-II imaging ability for guiding combined chemo-thermal therapy, and the soluble supporting base ensures that the needle arrows are embedded in the skin after insertion and endows the MNs with a separation ability to reduce the contact time of the MNs with the skin. In vitro studies showed that Flav7 + DOX-loaded MNs exhibited adequate insertion abilities, stable thermal properties, and desirable light-activated melting effects and drug release capabilities. In vivo studies showed that the Flav7 + DOX-loaded MNs presented a remarkable NIR-II imaging ability, a good biosafety to the major organs, and a strong tumor-killing ability. It is worth noting that all of the treated breast cancer mice survived for 50 days without tumor recurrences or major organ damage. This study presented a promising MN system loaded with the multipurpose small molecule Flav7 that can be used for high-efficiency light-activated drug release for chemotherapy and high-performance light-controlled thermotherapy of tumors and also for remarkable NIR-II fluorescence imaging to guide chemo-thermal therapy.

Accurate Fluorescence Diagnosis of Cancer Based on Sequential Detection of Hydrogen Sulfide and pH.

Cancer ranks as a leading cause of death in every country of the world. However, if they are discovered early, a lot of cancers can be prevented or cured. Discovering and monitoring cancer markers are the main methods for early diagnosis of cancer. To date, many fluorescent probes designed and used for early cancer diagnosis can only react with a single marker, which always causes insufficient accuracy in complex systems. Herein, a novel near-infrared (NIR) fluorescent probe (CyO-DNP) for the sequential detection of H2S and H+ is synthesized. In this probe, a heptamethine dye is selected as the fluorophore and a 2,4-dinitrophenyl (DNP) ether is chosen as recognition group. In the presence of H2S, CyO-DNP is transformed into CyO, which exhibits an intense fluorescence at 663 nm. Then, H+ induces the protonation of CyO to obtain CyOH, and the final fluorescence emission at 793 nm significantly enhances. Owing to the low cytotoxicity and the NIR fluorescence emission, CyO-DNP can sequentially monitor endogenous H2S and H+ in cancer cells and image exogenous and endogenous H2S and H+ in mice. It is worth mentioning that CyO-DNP can effectively avoid the false positive signal caused by the liver and kidney and discriminate normal mice and tumor mice accurately. For all we know, CyO-DNP is the first fluorescent probe for early accurate diagnosis of cancer by sequentially detecting H2S and H+.

Rapid recognition of di-n-butyl phthalate in food samples with a near infrared fluorescence imprinted sensor based on zeolite imidazolate framework-67

Di-n-butyl phthalate (DBP) as a plasticizer is widely used in food and chemical industries. It is harm to human health when it appeared in food and water. A novel near-infrared (NIR) fluorescence molecularly imprinted sensor based on CdTe quantum dots and zeolite imidazolate framework-67 was developed with a sol–gel polymerization method for rapid and sensitive determination of DBP in foodstuff rapidly (only in 1.5 min). The fluorescence imprinted sensor provided a rapid detection method for DBP in the linear response concentration range of 0.05–18.0 μM with a low detection limit of 1.6 nM. Compared with previous fluorescence imprinted sensor, it behaved faster response speed and lower detection limit for determination of DBP. The fluorescence imprinted sensor was used to detect DBP in real samples successfully with satisfied recoveries of 97.2–106.4%, suggesting a potential application in food analysis.

Developing fluoromodule-based probes for in vivo monitoring the bacterial infections and antibiotic responses

Recently, antibiotic resistant has become a serious public health concern, which warrants new generations of antibiotics to be developed. Pharmacodynamic evaluation is crucial in drug discovery processes. Despite numerous advanced imaging systems are available nowadays, technologies for the sensitive in vivo diagnosis of bacterial infections and direct visualization of drug efficacy are yet to be developed. In this study, we have developed novel near-infrared (NIR) fluorogenic probes. These probes are dark in solution but highly fluorescent when bound to the cognate reporter, fluorogen-activating protein (FAP). We established the in vivo bacterial infection model using FAP_dH6.2 recombinantly expressed E. coli and applied this NIR fluoromodule-based system for diagnosing bacterial infections and monitoring disease progressions and its responses to a type of antibiotics through classic mechanism of membrane lysis. This NIR fluoromodule-based system will discover new information on bacterial infections and identify newer antibacterial entities.

Effects of graphene nanoplatelets on bio-based shape memory polymers from benzoxazine/epoxy copolymers actuated by near-infrared light

Novel near-infrared (NIR) light-induced bio-based shape memory polymers (SMPs) were prepared from copolymers of vanillin/furfurylamine-based benzoxazine monomer (V-fa monomer) and epoxidized castor oil (ECO). Incorporation of graphene nanoplatelets (GNPs) as photothermal fillers into the copolymers provided shape memory properties under near-infrared (NIR) light actuation. The effects of GNP content on photothermal, thermal, dynamic mechanical, morphology, and shape memory properties of the bio-based benzoxazine/epoxy copolymers (V-fa/ECO copolymers) were investigated. The results showed that the addition of GNPs significantly improved the photothermal, thermal, and dynamic mechanical properties of the copolymers. The uniform dispersion of 3 wt% GNPs in the V-fa/ECO copolymers resulted in the highest shape memory performance with shape fixity of 92% and shape recovery of 99% upon NIR light actuation. The recovery time decreased with the increment of GNP content, and the V-fa/ECO copolymers filled with GNPs displayed good execution in the repeated fold-deploy, in which the shape fixity and shape recovery values were close to the original specimen. Therefore, the outstanding properties of V-fa/ECO copolymers filled with GNPs had a potential to be excellent SMPs under NIR actuation.

Reversible polysiloxane-based near-infrared fluorescent probe for monitoring the redox cycles between HClO/SO2 in mitochondria and in vivo

The redox homeostasis between hypochlorous acid and sulfur dioxide is closely associated with the physiological processes. However, it is challenging to develop reversible probes for detecting this redox cycle. Towards this end, we designed a novel near-infrared (NIR) fluorescent probe P-HClO-SO2, which integrates with telluroenzyme mimics for monitoring the changes of HClO/SO2 levels in cellular condition and in vivo. The unique probe P-HClO-SO2 could reversibly respond to HClO and SO2 and exhibit high selectivity, sensitivity, and mitochondrial target. This work may render a valuable advance on the redox processes within the cell redox regulation and in vivo.

Clinically translatable formulation strategies for systemic administration of nerve-specific probes.

Nerves are extremely difficult to identify and are often accidently damaged during surgery, leaving patients with lasting pain and numbness. Herein, a novel near-infrared (NIR) nerve-specific fluorophore, LGW01-08, was utilized for enhanced nerve identification using fluorescence guided surgery (FGS), formulated using clinical translatable strategies. Formulated LGW01-08 was examined for toxicology, pharmacokinetics (PK), and pharmacodynamics (PD) parameters in preparation for future clinical translation. Optimal LGW01-08 imaging doses were identified in each formulation resulting in a 10x difference between the toxicity to imaging dose window. Laparoscopic swine surgery completed using the da Vinci surgical robot (Intuitive Surgical) demonstrated the efficacy of formulated LGW01-08 for enhanced nerve identification. NIR fluorescence imaging enabled clear identification of nerves buried beneath ~3 mm of tissue that were unidentifiable by white light imaging. These studies provide a strong basis for future clinical translation of NIR nerve-specific fluorophores for utility during FGS to improve patient outcomes.

Synthetic infrared nano-photosensitizers with hierarchical zoom-in target-delivery functionalities for precision photodynamic therapy

Surgical assailment at the vulnerable subcellular organelles (e.g. mitochondria) by photodynamic therapy (PDT) is perceived as the most devastating approach to eradicate the tumors. Herein, we programmed a novel near-infrared (NIR) PDT construct illustrating appreciable hierarchical zoom-in targeting scenario, namely, primary cell-level targeting to carcinoma post systemic dosage and subcellular level targeting to mitochondria. Pertaining to tumor-targeting function, charge reversal chemistry selectively responsive to acidic tumoral microenvironments (pH 6.8) was implemented as the external corona of PDT constructs. This charge transformative exterior entitled minimal biointerfacial reactions in systemic retention but intimate affinities to cytomembranes selectively in tumoral microenvironments, thereby resulting in preferential uptake by tumors. Furthermore, the proposed PDT constructs were equipped with mitochondria targeting triphenylphosphonium (TPP) motif, which appeared to propel intriguing 88% colocalization with mitochondria. Therefore, overwhelming cytotoxic potencies were accomplished by our carefully engineered photodynamic constructs. Another noteworthy is the photodynamic constructs characterized to be excited at tissue-penetrating NIR (980 nm) based on energy transfer between their internal components of anti-Stoke upconversion nanoparticles (UCN, donor) and photodynamic chlorin e6 (Ce6, acceptor). Therefore, practical applications for photodynamic treatment of intractable solid carcinoma were greatly facilitated and complete tumor eradication was achieved by systemic administration of the ultimate multifunctional NIR photodynamic constructs.

Visualization of endoplasmic reticulum viscosity in the liver of mice with nonalcoholic fatty liver disease by a near-infrared fluorescence probe

Nonalcoholic fatty liver disease (NAFLD) can cause serious liver damage. Early diagnosis and effective treatment of NAFLD can greatly improve treatment rates. The initiation and development of NAFLD has been closely linked to endoplasmic reticulum (ER) stress, which might cause ER viscosity variations. Therefore, if the internal relationship between ER viscosity and NAFLD is clarified, an effective approach for early diagnosis may result. Herein, we fabricated a novel near-infrared (NIR) fluorescence imaging probe, Er-V, for monitoring ER viscosity through a molecular rotor strategy. Er-V exhibited a strong NIR fluorescence signal (at 626 nm) when the environmental viscosity hindered the rotation of the malononitrile group. Using Er-V, we successfully observed a significant enhancement in viscosity in the liver of mice with NAFLD. Therefore, this imaging method based on Er-V is expected to provide a new approach for early detection and diagnosis of NAFLD.

A novel indocyanine green-based fluorescent marker for guiding surgical tumor resection

Surgical tumor resection is a common approach to cancer treatment. India Ink tattoos are widely used to aid tumor resection by localizing and mapping the tumor edge at the surface. However, India Ink tattoos are easily obscured during electrosurgical resection, and fade in intensity over time. In this work, a novel near-infrared (NIR) fluorescent marker is introduced as an alternative. The NIR marker was made by mixing indocyanine green (ICG), biocompatible cyanoacrylate, and acetone. The marking strategy was evaluated in a chronic ex vivo feasibility study using porcine tissues, followed by a chronic in vivo mouse study while compared with India Ink. In both studies, signal-to-noise (SNR) ratios and dimensions of the NIR markers and/or India Ink over the study period were calculated and reported. Electrocautery was performed on the last day of the mouse study after mice were euthanized, and SNR ratios and dimensions were quantified and compared. Biopsy was performed at all injection sites and slides were examined by a pathologist. The proposed NIR marker achieved (i) consistent visibility in the 26-day feasibility study and (ii) improved durability, visibility, and biocompatibility when compared to traditional India Ink over the six-week period in an in vivo mouse model. These effects persist after electrocautery whereas the India Ink markers were obscured. The use of a NIR fluorescent presurgical marking strategy has the potential for intraoperative tracking during long-term treatment protocols.

Three kinds of porphyrin dots as near-infrared electrochemiluminescence luminophores: Facile synthesis and biosensing

Three kinds of porphyrin dots, including TCPP dots, ZnTCPP dots and TCPP-based metal organic framework (pMOF) dots, have been subtly synthesized for the first time by a universal straightforward exfoliation of bulk porphyrin aggregates or pMOF. To explore their ECL application, a novel label free “signal-on” ECL biosensor for ultrasensitive detection of Pb 2+ was developed based on TCPP dots as DNA intercalators and DNAzyme-based hybridization chain reaction signal amplification. • Three kinds of porphyrin dots are subtly prepared by a simple and universal exfoliation. • The novel porphyrin dots show excellent annihilation ECL activity. • They all exhibit stable and robust near-infrared co-reactant ECL performance. • A label free ECL biosensor is established for trace Pb 2+ detection based on TCPP dots. • The porphyrin dots as ECL emitters give a new proof of concept. Exploring novel near-infrared (NIR) luminophore with highly efficient and benign is strongly anticipated for electrochemiluminescence (ECL) evolution. Here, three kinds of porphyrin dots including 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) dots, ZnTCPP dots and TCPP-based metal organic framework (pMOF) dots have been subtly synthesized for the first time by a universal straightforward exfoliation of bulk porphyrin aggregates or pMOF. These as-designed porphyrin dots perform excellent annihilation ECL activity, also exhibit stable and robust cathodic or anodic NIR ECL properties with different coreactants (potassium peroxydisulfate, hydrogen peroxide or tri-n-propylamine) in aqueous phase. Especially, the ECL efficiency of three kinds of porphyrin dots in S 2 O 8 2− cathodic system are 56, 44, 39-fold higher than that of the Ru(bpy) 3 2+ standard, respectively. As a new type of ECL luminophores, TCPP dots coupled with a lead ion-dependent DNAzyme and hybridization chain reaction cycle amplification are used to fabricate a label free “signal-on” ECL biosensor for ultrasensitive detection of Pb 2+ . A dynamic range from 10 pmol·L −1 to 1 μmol·L −1 with a low limit of detection (1.2 pmol·L −1 ) is obtained. These porphyrin dots provide evidence for the use of organics-based dots as new NIR ECL luminophores for fundamental ECL research, and highlight the significance of small-sized organic nanomaterials in ECL sensing applications.